The political system

Why are people so apathetic? Why are politicians hated and politics derided?

I can't be certain, but I can offer my views on what's wrong with political system. This comes from a conversation I had recently which started out with lawyers.
We have one vote out of roughly 68,500 in our constituencies. We vote for one of four or five parties that have won any seats at all, but typically we live in constituencies in which we are hopelessly outnumbered by a solid block of people who can be relied apon to vote for one party, making that constituency a 'safe seat'. Therefore, for most people, to vote is pointless because if those people vote as they are almost certain to do the contrasting vote has no effect at all.
The first past the post system therefore encourages apathy by giving most votes no effect at all. Although individual votes can be said to have minimal effect compared to the whole 60,000,000 (or 44,000,000 who can vote), or even to the 27 million who did vote at the last election, a proportional representational system would make each vote useful, because they would all add to a party's total.
The benefits of our constituency system are supposed to be that we get representation for our area, and perhaps that we can pick our own candidates.
We clearly do not pick our candidates: we have centrally-dictated candidate lists, all-women short-lists, or even candidates parachuted in from elsewhere. In most places candidates are party members, selected by the fellow party members of the area. This requires a fee, making participation in candidate selection a privilege, not an integral part of the democratic process. Of course, we can vote for independent candidates, a benefit that PR does not give (in all implementations of which I know). Independent candidates, however, need very special circumstances in order to stand a chance of winning. This is one of the major benefits of our system, so I should take some time to examine why it never works.
Firstly, we have voter apathy; voters are not taking the time to investigate who wants what, and so an independent candidate has the disadvantage of not generally being known. Once apon a time, when a person could be known in an area the size of a constituency, an independent candidate might have been able to raise a sizeable following, but now he needs money for lots of advertising.
This is the second point: political parties receive large amounts of funding from donors and businesses, and a candidate representing one benefits from national spending and a local budget, as well as having a pre-arranged set of people to help with campaigning; in marginal seats, where a person's vote might have meaning, parties often send in campaign teams to help. People grow up with constant exposure to political parties and their supposed ideals, which counts as greater advertising and is a definite barrier to entry for new applicants, such as independent candidates.
Thirdly, and understandably, a deposit is required for a candidate to stand, to pay for the administrative costs of including the candidate in official documentation. This is refunded if the candidate does poll a relatively small proportion of the vote, but is deliberately sufficient to scare off those without spare cash. I don't think that it's a terrible idea: it's necessary to prevent everyone standing, but it will have bad effects too.
Of course, independent candidates suffer from the same disaffection with politics as other candidates and probably more so, since they rely on voters being interested enough in local issues to realise that the independent candidate represents the best option despite having less money for advertising. This disaffection is the subject of the whole post, so I won't go into it further.
Fourthly, independent candidates suffer from the same problem in parliament that voters have in constituencies. Even if the voters are motivated enough to elect one, he can do nothing much in parliament without the support of one of the behemoths of political parties; private members' bills are renowned for rarely becoming legislation; recent legislation in which ideas from local areas are taken by councils and proposed for consideration in law through a definite framework was said on Radio 4 to be a very rare example of a private member's bill actually making it all the way through.

So we can't have a nice load of independent candidates actually representing local interests. What's wrong with parties?
Political parties need cohesion. MPs are required to toe party lines, which can conflict with the best interests of the country or the constituency (or both, of course). Keeping the current system is justified because of the representation of individual regions, and the ability to have 'your own' MP who officially represents you (and 68,499 other people), rather than the other 60 million people. The whole purpose is lost if MPs are actually elected on the basis of national campaigns and policies.
MPs are co-erced into behaving by the party 'whips' through a number of mechanisms, on which I am not an expert. Examples include the whips' control of who goes on fact-finding expeditions (also called holidays) to foreign climes, placements on committees, which might either be a special interest of the MP, or have paid positions, and junior ministerial posts, which are both paid and good for the career (either in or out of parliament; 'revolving doors' is a phenomenon that I should address later).
Of course, behaving does not involve helping the party keep all its manifesto commitments, which are supposedly the basis of elections (now that we've established that they're not won by party candidates campaigning on local issues). Political parties don't even stick to these commitments. Labour's recent commitment not to introduce top-up fees for university education was utterly ignored once Labour came to power. If we can't rely on the promises that the political parties make, but we must vote for a party because independent candidates have so many problems, on what basis can we decide to vote?
I have heard people suggest that the presidential system of voting for candidates is a good way of understanding our current voting system: we elect people who we like, and trust them to run the country for us for five years. They suggest that people can't make manifestos to cover five years of events, with that much time necessarily containing unpredictable problems and crises, and that we shouldn't expect anything from manifestos.
To start with, I don't think that the unpredictable nature of five years makes manifestos not worth adhering to. It ought to be perfectly possible to be both trustworthy and reliable in dealing with promises and new events. At best, therefore, it merely adds another concern to an election.
But we don't elect a supreme leader whose judgement must be sound because of the power we let him wield. We elect, supposedly, one person to represent our region in a national assembly whose overall judgement must be sound. If we were to elect a supreme leader, I think we should just call it democratic tyranny and forget about parliament altogether, which is what Tony Blair has been working towards.
At the moment we do not elect a leader on the basis of his character. We don't elect the leader at all: the party leaders are chosen by party members (or by the currently sitting MPs), and we only get to choose a party. The party policies, meanwhile, are settled by a clique of movers and shakers at the head of each party.
So we do not have a presidential system because we do not vote for our supreme leader. We do not want a president, especially since we have not split the various jobs of running the country as clearly as the Americans have, so the president would have far too much power, because parliament has power over almost everything (that it hasn't yet signed to Brussels).
Furthermore, unforeseen events can be acted on under a set of principles that can indeed be enunciated beforehand, and promised. We would not need to vote by character if parties actually still had principles. All they have nowadays can be summarised by the recent campaign poster of Mr. Cameron, whose shining face dominates some vapid guff about cutting the deficit and not the NHS, as if some other party were truly promising the opposite.
We clearly have moved towards elections based on character, and not on principle, the parties espousing no principles, having few meaningful policies and not even keeping to them. This does not sit well with our system, all the benefits of which are in direct opposition to elections fought on the basis of a single leader. We have the worst of both worlds: elections fought with nothing solid and campaigns designed to appeal to the general population, and a system which is incredibly undemocratic when abused in such a way, and whose benefits are lost by national campaigning.
Just to illustrate how amazing the situation is, I will repeat it, with figures to demonstrate the point. We are electing our MPs on the de facto basis of PR campaigns that use the party leaders and worthless rhetoric (rather than solid argument) as their material. We are, therefore, electing parties nationally, as we would by PR. However, our current system was not designed for such shallow electoral processes, and we therefore have Labour in power, with 55% of the seats in parliament and 35% of the vote. The Conservatives got 32% of the vote and 31% of the seats and the Liberal Democrats 22% of the vote and less than half that, 9.6%, of the seats in parliament. We are running a PR system (both proportional representation and public relations) , as I have said, but we aren't even getting it right.
People argue that a PR system would give undue power to the minorities; that they can hold things up, or act as power brokers. I can't help but note that the current system is hardly fair and representative, with 40% of voters being misrepresented! It would be hard to get much worse, and I would far rather have power too spread out than too concentrated in the hands of, for example, Tony Blair.
He serves as a fine example of the folly of our system. We voted him in on either the basis of manifesto or character. A likeable man of good character should, we are told respond to events in a way that represents the population. This is why our presidential Blair went to war against the popular will because he wanted to make George Bush happy. Alternatively, we should forgive such mistakes, because we elected a party and its manifesto. This is why we got a string of broken promises, such as tuition fees and the breaking of the self-imposed golden rule of fiscal management.
We got signed up to Lisbon without getting a say in it and we got Northern Rock bailed out, at great cost and for no good purpose, because it would have harmed mainly Labour constituencies. Labour has multiplied the number of sweeteners available for whips to offer recalcitrant MPs, increased the renumeration for such perks (evading limits on MPs' incomes without actually being open about it, and again making it harder for independent MPs, who cannot be expected to get such positions as easily).

Our politicians clearly do not act in the national long-term interest, short-term interest, or for their constituencies. So what else might motivate them?
I could start in a number of places, but first I think I'll mention the incredible disaster that is PFI; the private finance initiatives that cost 3-4 times more, on average, and serve only to make the governments ledgers look good in the short term because they aren't recorded there as debt. Here we have politicians acting in their own interests: to make themselves look good: far better than actually ought to be possible. This fundamental dishonesty can be blamed on the media and the population, for getting so agitated over normal problems, but is within the politicians' power to avoid.
It has become known as 'spin'.