Except that people didn't vote lib Dems for them to be in government no matter what, they voted for lib dem policies.
And one of the main Lib Dem policies was, and has always been, to bleat on about how wonderful and great and mature European consensus, coalition politics is. And therefore how the Lib Dems believe in consensus building with other parties, coalition, and electoral reform to make that more likely.
They also very clearly stated before the last election, that they would enter coalition talks with whoever was the largest party. They were repeatedly very clear about this. They have been very clear on this since they were founded in the late 80s.
Any voter who voted Lib Dem knew exactly what they were going to get. Or if they didn't, it's their own bloody fault. And they should stop whining and take responsibility for their own actions. This information was not hidden, or secret, or a surprise to anyone with even the vaguest knowledge. Our political system first of all needs better voters. Before we can improve our politicians and political discourse, we need voters willing to at least take a tiny amount of their time to decide. If we don't want politics to be a beauty contest, then you have to stop voting for whoever performs best on telly and start devoting at least a few hours, every four years, to working out who we agree with.
They got into government based on the votes of people that they would never have got had the voters realised what could happen as a result of voting lib dem.
Anyone who didn't want the Conservatives in power had the choice to vote Labour, or some other party. If they chose to vote Lib Dem after Clegg had said he'd do a deal with whoever got the most seats, then they were obviously willing for that coalition to happen. That is the only interpretation the Lib Dems could take, short of asking each of their voters individually why they'd voted for them. I have zero sympathy.
Now I admit that the Lib Dems seem to have been attracting a 'none-of-the-above' protest vote before 2010. And a lot of that seems to have now shifted to UKIP. This is the interpretation that many pollsters I've read have put on the quite large number of 2010 Lib Dem voters who've now switched their alleigance to UKIP (or tell pollsters they have anyway). Well, if you don't want any of the two bigger parties, why not vote Monster Raving Looney, or Respect or Socialist Labour or something? Because the Lib Dems have been talking about coalition for their entire history - and took it at the first opportunity (as they always said they would). Also how are the politicians supposed to interpret votes, if people are going to switch their votes from a socially liberal, economically centrist, massively pro EU party to a socially conservative, anti-EU one? As I said, people have got to take some responsibility for the entirely predictable consequences of their own actions.
personally speaking I think a system without any party whips where the MPs really do represent the interests of their constituency rather than those of their party would be one of the best things that could happen to this country, even if PR is completely forgotten.
This system would only be workable if the electorate were willing to invest a lot more effort into politics than they currently seem to be willing to.
Having no whips also means it's much harder for the electorate to know what they're voting for. It's all very well to talk about MPs acting on conscience, but in the system we currently have most people vote party, not MP. By voting party, they get to vote on a manifesto. That means the MPs then have the obligation to walk a tightrope between the voters who wanted the manifesto they voted for, and those who may know the MP, and have voted for them to use their conscience. There is no perfect system, but the downside of not whipping (and PR with constant coalitions) is that voters vote for one thing, and don't get to find out what they will actually get until after the election. Which is exactly the problem you're complaining about in your post.
I'm personally against PR and non-whipped MPs for this reason. However, if the main parties are unable to get more than 40% of the voters for one more election, I'll switch to voting for PR, because first past the post is too unfair if parties can get an overall majority with only 35% of the vote. Well only Labour can, due to the way our system was biased by the 97 boundary review (and cahnging demographics) - the Conservatives need about 39%, and Labour to get less than 32% (very roughly. Whereas Labour could theoretically get an overall majority on 36% each - well that's before Scotland went SNP. Who knows what'll happen now.