I don't agree with you about Brexit - my reasons for voting for it are to do with history and the state of the world today, not racism and British exceptionalism, and I'm sure I'm not the only one.
However, I do agree about the failure of so many people when it comes to voting. Especially the young, here in the UK.
The answer, of course, is compulsory voting, with the addition of an extra box marked "Abstain". If more than a given percentage abstain in any election, then a National Administrative Government should be formed to keep everyday work going while the political parties go off and figure out what they're doing wrong!