> I'd say it's mostly feeling a loss of control, which they couldn't place and our politicians were not open enough about explaining that this loss of control of the population was caused by.... the politicians themselves.

Yeah, the EU is essentially run by the national governments.

However, they typically (and the UK were particularly bad here) use the EU as a scape-goat for unpopular decisions even when they'd agreed to them in Brussels.

Understandable, but bad for Europe/EU in general.