Yes but there is no reason for the libdems existence now, just vote tory. The libdems serve no purpose (except giving the tories power). Not that they served much purpose before.
Yes, there is. The liberals currently have made the coalition more liberal and fair than a tory majority would have been (see rising tax allowances, increased capital gains tax, an increased focus on civil liberties and so on).
They enable the coalition to be less right wing than a tory majority would have to be due to not having the need to appease the more extreme right (economically and socially) of the party.
How is that not serving a purpose?
If Blair and Ashdown's plan for 1997 had come off (that was abandoned due to the labour landslide), the party would have served a similar purpose, to nullify the hard left (economically and socially) of the labour party.
Would that have also been pointless?
You are obviously of little experience, Michael Foot showed what unelectable is, if you look at Hague, IDS etc all of whom were comprehensibly rejected by the electorate, the libdems have made them important government ministers. Just because it satisfies your beliefs doesn't legitimise it.
Foot wrote the longest electoral suicide note in history, but remember that Kinnock couldn't even depose Major in 1992. It took Blair's reforms to make the labour party electable to most people. I welcome the shift back to the left if it occurs, it will keep them out of power for far longer.
As for IDS and Hague being rejected by the electorate, they haven't been, otherwise they wouldn't still be MPs. Their vision as leaders of the party may have been, but that is a different issue entirely.
the problem is self interest and short sightedness
I agree, which is why we need strong restrictions on the ability of the state to misuse power to appease those instincts.