I've always said that not every one who voted Leave was a racist (in fact I'd say the large majority weren't), but there are people on both sides of the argument who hold bigoted views. I daresay that some read what I say about politics on here and think I'm a bigot, but I can at least say that I've held the views I hold now all of my life and, unless there is a process whereby you suddenly change your political views when you reach a certain age, I'll have them until I die.
This leads me on to the bit of what I said that you did not address. I always think that it's a bit hypocritical when people who are old enough to have lived through the sixties and early seventies as teenagers or young adults have a go at today's youngsters for their political activism. This is almost always aimed at those who are supporting left wing causes and parties and, in very many cases, conveniently ignores the fact those kids are only doing exactly the same things as they were getting up to fifty years ago - all of the polling evidence strongly supports the view that the older range of the voting spectrum are right wing by a large majority, but I'm practically certain that any survey of the babyboomer generation taken between, say, 1965 and 1970 would have produced a completely different conclusion.
Regarding your last paragraph. More than any election I can remember, the EU referendum caused friends, family members and other acquaintances to fall out. Around this time last year, there were plenty of media stories about sons and daughters not talking to their parents because of their differing opinions on Brexit. I've also read some recent stories where people who had fallen out badly were now getting along better because they'd agreed to disagree - that's what people tend to do when they have profound differences on a subject. In the case of me avoiding political conversations with the senior citizens I talked about, all I'm doing is acknowledging that they aren't going to change my opinions, and, given the force with which they argue on the subject, I'm certainly not going to change theirs.