Oh, enough [Patronising. Good start]. The most diverse places don't have these issues [By definition, the population of a place that is 'diverse' has arrived at a happy accommodation; obviously, they won't have such issues. Which is wonderful]. This phobia is occurring mostly in places that are homogeneous [Obviously, places which have previously experienced little cultural change are going to experience more anxiety in relation to immigration. But what to do about it? Dismiss such feelings?]. It's just classic racial resentment presented by mostly uneducated people whose identities are wrapped up in petty mythologies about themselves [Dismiss it is, then. Your conflation of racism and the 'uneducated' is pure bigotry. Aren't all cultures mythological to a greater or lesser extent?]. It's not complex [It is].
They are not experiencing sweeping demographic changes in their own neighborhoods [Who are 'they'?]. Besides, change occurs, populations move in, and some of them don't hold your values [Kind of contradicted your previous sentence, there, didn't you?]. You don't own the future. [Now I see why you don't think it's complex. Native people should just suck it up. Shit happens? Does this apply to any native population, anywhere in the world, experiencing significant levels of immigration?].
You are free to move [Again, does this apply to any native population, anywhere in the world, experiencing significant levels of immigration?]. Brexit is not going to do anything to change demographics, or immigration [I voted 'remain']. It was sold to the plebs [bigotry] as the solution, but that was just cynical marketing. Once they realize nothing is going change in that regard, they [who are 'they', the plebs or the cynical marketers?] will move on to their next self-defeating big idea.
The world has been through this before, and it always ends the same way. People are not complex, they are base, and easily defined [speak for yourself]. Fear is not an excuse [but it is a reality]. It's just being used a rationalization for a racial, and cultural resentment that was always there [Sometimes fear is just fear].
But as someone else said, as an American, I almost get a cruel satisfaction from watching England cripple itself. It has been America's lapdog since the end of WWII, and now it will be even more dependent on it. It's just trading dependencies. England already has privileged trade status with America. It can't get much sweeter. [You've digressed, here. And I think you might have started touching yourself].
I think that's what it mostly comes down to. England's national self-image is so tattered that it's now resorting to what you saw happen in Germany pre-Hitler. Hitler used nationalism to prick savage tendencies that gave him even more power to create his own agenda, and the public went along with anything he devised after that point; as long as he told them how great they were. They took a single issue, and traded in all others for the pleasure of scapegoating their failures.
Virulent nationalism is almost always a response to a society's low self opinion in an ever changing world. Somebody else must pay for making us feel small.
[I sort of agree with some of the points you're clearly struggling to make in the previous two paragraphs -- I can do patronising, too. However, none of it speaks to what I was talking about: human beings finding it difficult to cope with change. In fact, the notion that such people are 'savage' and simply looking for scapegoats is simplistic and, once again, bigoted.]
Stop trying to spice it with a sense of virtue, and reasonable anxiety [Being virtuous and reasonable is kind of my bag]. There is nothing reasonable about it. Most people didn't even bother to examine the details. It was a temper tantrum [I assume you're talking about brexit again. I voted 'remain'].