Whether or not it's the most pointless job *now* is moot, but it clearly shouldn't be. If elections are reduced to just two plausible choices then that is not exactly something to be proud of.
On the other hand, the Lib Dems have to blame themselves for that; the last ten years have seen some sadly disastrous decisions on their part, even if at least some of them made sense at the time. Going into Coalition with the Tories was probably their only viable shot at having much actual influence, but they seemed to waste those five years and angered more or less everybody in the process, and it's not clear that they've really recovered from that or will any time soon.