The Lib Dems have always stood in the centre on British politics though; indeed, that's probably their main differentiation to the other two. As for the idea a political party should be punished for taking power, well...
Not quite true. Liberal Democrats across the board share liberalism as an ideology. They oppose e.g. the snoopers charter, 28 days detention without charge etc. There's a universal desire to empower the poorest.
However, in terms of economic left/right, the party is actually quite varied. The Orange Bookers (Clegg, Laws, Huhne, Alexander, Cable... basically the main Lib Dems in the coalition) occupy the centre/centre-right, sitting closer to classical than social liberalism. They believe in generally shrinking the state and tax cuts for all but the richest, but not privatisation en masse and tax cuts for the rich like neoliberals believe in, and they would broadly support the NHS, welfare etc. Basically, they see the state mainly as a means of supporting the poorest but not much else. These Lib Dems view forming the coalition as being morally right (even if they also think it was a political mistake for the Lib Dems, which it obviously is).
The Beveridge Group and its supporters, on the other hand, occupies the centre-left, further left than the majority of Labour, but not as left as the most leftward of Labour members. They are full on social liberals. In my experience, most Lib Dems fall into this category, and it's mostly this type of Lib Dem that left the party following the Lib Dem dealings with the Tories. They believe it to have been wrong, morally and politically, for the Lib Dems to go into coalition. So it's a bit infuriating that the Orange Bookers, a relatively small faction in the party, managed to hijack the party and drive away the core supporters. Of the 8 remaining MPs, at least 4 are of the Beveridge Group, including the likely next leader, Tim Farron. If Labour swings to the right in reaction to Ed's failing, there's no doubt in my mind that Lib Dems will swing to the left, distance themselves from the Orange Book years and attempt to claw back the social liberals.
Nick Clegg is going to have the hardest ride of any MP in the next 5 years. Ed Miliband will fade into the backbenches. Nick Clegg will sit amongst his 7 other MPs, self-aware of how much the rest want to distance themselves from him and his time as leader. Putting down his decisions will be the only way the Lib Dems will claw back its core supporters, so he may have to be ready to be a punching bag for his next leader. I wonder whether he feels it would have been better had he lost his seat...