Brits never experienced the tangible benefits of EU membership because they actively excluded themselves from both Schengen and the Euro. It's not really surprising that many reject something that is only an abstract macroeconomic set of rules to them.
Contrast this with public opinion in Germany back before the common currency: most German EU supporters were openly afraid that the Euro could seriously endanger their economy, but they considered it well worth the risk just for complementing the convenience of open borders with an end to the hassle of dealing with foreign currencies.
To anyone with a bit of critical thinking ability, macroeconomic decisions are close to a coin toss: both sides have good arguments and nobody has convincing data to back up their claim (if there was there wouldn't be a decision to be made).
Quest over! If you're actually interested in understanding the reasons for Brexit and you should before making such comments, try this https://briefingsforbrexit.com. Not recommended for those with a short attention span.
"Briefings for Brexit is a small group of volunteers, mainly academics, who set up the website in 2017 in order to provide reasoned factual material to help to inform the national debate on Brexit. Most of its members did not previously know each other. The two co-editors are Graham Gudgin and Robert Tombs, both of Cambridge University. Its contributors come from a range of academic disciplines and universities, and cover the whole political spectrum: their names can be found on our website. The group has no links with any political party. Neither of the editors receives any payment, not do any of the contributors. The newsletter editor, a student, receives a small payment. Briefings for Brexit is entirely funded by well-wishers."
Cool, how would I go about donating £10 to them? Would you say that this kind of small donation makes up the majority of their funding? Who are the large backers?
So this is totally above board, unaligned and not paid for! /s