And that's exactly where all of this thinking falls apart: in an equal, democratic society no group should be able to decide who's a good or a bad citizen. There's only the laws of the country that should count and everyone has to obey.
You should soften up your idea of "migration" because there is no inane biological quality in humans that make them good or bad.
99% of "immigration problems" are because of poverty and inequality (both too little or too much money can influence behaviour) and not because of some sort of gene that makes human behave badly.
That's just made up claim there's no evidence to support this. Even if it were true it's not the taxpayers responsibility to import all the degenerate murderers and rapists from all over the world in the hopes of civilizing them.
Why should someone from a developed country agree to give up their safety and wealth to run this ridiculous and deadly experiment?
That's just not how any of this works and I think you know it. You're just being obtuse, although I don't know why.
I have to say, that not every country is the same. United States from an outsider perspective seems like you could come from anywhere and look like anyone, as long as you pleadge your allegiance to the flag and become and 'American' you will be accepted. This is probably because US has a short history, and it wasnt too long ago when it was literally all migrants.