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).
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).