I'm reticent to share because you have now more than once hinted to the fact that you wouldn't listen. What's the point of making a lengthy argument if the listener is telling you in advance that he'll chant 'la la la' while you're doing so?
But fine. I'll try to make it short to reduce the inevitable frustration.
Let's take the pretty central, known and well-publicised issue of immigration. Let's pick some random Belarus businessman who wants to move to the UK. Now, absent the EU this bloke'd have to go through UK immigration and, for some reason we won't get into here, he'd be rejected and would have to find some other place to move to. Now, with the EU, he could go to a different EU country -- say Greece --, and perhaps get a more lenient treatment that allows him to get a EU passport and therefore move to the UK despite the fact that they would've otherwise rejected him. So far that's just the situation, not the argument.
Now, given that, and unless I'm mistaken about that process, I would find that some UK resident saying they'd like to have control over their immigration process, for any reason, to be rational. After all, every country has their own rules and standards, and even if you or I disagree with those of the UK outside of the EU, I think it's completely reasonable to expect a citizens to want their country to be able to apply those rules. Now, if we take some of that to extremes it leads to abuse, as usual, but it doesn't change the basic concept that a sovereign state, and a specific culture, would be quite reasonable in wanting control over who can come and live on their territory.
Would you not agree? And please don't make this about racism, because it's entirely irrelevant to the argument above.