I see your argument but I don't think it's about just the MPs when it comes to the EU. The entire liberal establishment is out of kilter with the majority in the country. By contrast I reckon if we had a referendum on JC the result would be pretty much in line with the views of most Labour MPs.
I think it's the distinction between grass roots voters re the EU and grass roots momentum activists re JC. Two sets of people who couldn't be more different.
I would argue that UKIP's platform is hugely controversial to many Leave voters as are the characters involved in that party. I certainly wouldnt ever vote for them despite voting Leave. You argue that UKIP was the option to vote for at a GE if one wishes to leave the EU but it is not that...