Mikey
I loathe UKIP as much as you do, we've had many conversations about it.
But you're really being quite childish in this question. Nobody expects UKIP to win the General Election. Not even UKIP. It's not really what they're aiming for (and yes, before you start, it is perfectly valid to enter an election with a goal other than winning it).
What UKIP want (or rather what they seem to want from an outsider perspective) is to affect national politics by changing what people are talking about. In terms of Westminster, their ambitions don't seem to extend beyond getting one seat. The fact that they are even there gives the EU issue a higher and more consistent visibility than it would otherwise have.
We really have nothing to gain by wilfully re-imagining UKIP as some kind of crusade to take the Commons and then mocking its inability to do that. That's called a straw man, and it's a fallacy.