FFF.......what you have said may be true, but when the British people were asked just a few years ago, to depart from "first-past-the-post", the referendum was soundly defeated. So, UKIP and all the other minor parties will just have to play by the same rules as everybody else.
The Libs were in just the same position a few years ago, but still managed to go from political obscurity in the West Country, to power-sharing within a few years. The same is even more true of the SNP...they only had 6 seats in 1997 but managed to achieve 56, less than 20 years later.
But it doesn't really explain why Farage himself is so incapable of gaining a seat for himself, especially after so many attempts. He is, after all, the most recognisable of political Leaders in Britain today. He targets by-elections in seats most likely to contain potential UKIP supporters, but fails, utterly.