He's never been a MP, UKIP has never been considered a "major party" (how is this even defined?), there was no election in 2014, UKIP won 12.6% in 2015. He's clearly representing some people but your facts are way off.
That's very interesting about the official "major party status", thanks for sharing that. I was only considering General Elections, which are a fairer representation of a parties vote share (despite FPTP) as not all councils vote in local elections each year.
Worth remembering the dirty tricks employed against him:
'The election of a Conservative MP could have been declared void if he had filed accurate returns that showed he had overspent on his campaign to beat Nigel Farage, a court has heard.
Craig Mackinlay, an accountant, stands accused along with his election agent and a party official of deliberately submitting “woefully inaccurate” expenditure returns.'
As an electoral force, UKIP were very successful in European elections. It is reasonable to say that they were a major consideration in deciding to call the referendum.
https://en.wikipedia.org/wiki/2014_United_Kingdom_local_elec...
https://en.wikipedia.org/wiki/2014_European_Parliament_elect...
https://en.wikipedia.org/wiki/UK_Independence_Party#Entering... "In March 2014, Ofcom awarded UKIP "major party status"."
https://www.ofcom.org.uk/about-ofcom/latest/media/media-rele... "Ofcom’s initial view is that UKIP may qualify for major party status in England and Wales for the General Election and English local elections on 7 May 2015."
https://www.bbc.com/news/uk-politics-31906154 "Ofcom says UKIP, but not Greens, are 'major party'"