Xenophobia usually means hostility to people in one's environment who are perceived as outgroup because of ethnicity.
That is not necessarily implied by a wish to be governed by people perceived as ingroup.
Indeed. It seems to me that "I would prefer Britain to be governed by the British and not the Germans" (for instance) would only be xenophobic if it were based on fear or hatred of German people. I have no problem with Europeans, who I'm sure are fine people for the most part. I simply don't wish to be governed by them.
Think of it like a family. My family gets together to hang out in little gatherings sometimes. I wouldn't want my neighbours to come to those gatherings, not because I hate or fear my neighbours but because they're family gatherings and my neighbours are not my family.
Let's take this context of ethnicity, ingroup/outgroup, and government and think of the mayor of London, Sadiq Khan. Can you see how your attitude might cause problems?
No, I cannot. I've said I think Britain should be governed by the British. Mayor Khan is British. What's the problem that would be caused by my attitude, exactly?
For that matter, would it be possible for Scotland to stay part of the UK if everyone shared your approach?
Huh? If the people of Scotland took the view that Britain should be governed by the British, then I would think that would be a reason for them to stay part of the UK.
I assume that what you mean is that if the Scottish took the view that Scotland should be governed purely by the Scottish people, that would be a problem? That's not my approach. But sure, if they thought that way then they would leave the UK. Of course the last time anybody asked them, they didn't think that way.
Why are people happy to form some collectives but not others? What is special about an EU level cooperation that people focus on the issue of who makes the decision as opposed to what costs and benefits the cooperation gives.
That's a good question. I made a comparison to family gatherings earlier; one could ask why somebody should care about their family more than their neighbours - wouldn't it be a better party if the neighbours came too? And I couldn't argue that they're wrong; I can merely say that I disagree. In the end, those people you think of as "we" and those you don't are always going to be a subjective sort of thing.
It is the focusing on the who, which in my view moves the issue toward xenophobia. When someone complains they don't want Germans deciding on acceptable pollution rates instead of complaining that the pollution rates are too high, they have crossed the line.
I disagree. I think that line gets crossed when somebody doesn't want Germans deciding such things because they don't like Germans or perceive Germans as unpleasant, untrustworthy, etc.
And of course there would be many such people who voted for leave. It's a shame to be in such company, but it's an imperfect universe.
As for me, I could think that Germans are the finest, smartest, most moral, most all-around wonderful group of people in the history of the human race. I'd still prefer that they didn't run my country.