I'm just engaging in common-sense ethical reasoning. It seems wrong to require that all whites employ a much higher bar for hiring blacks. And, I have the same intuition about requiring all Americans employ a much higher bar for hiring foreigners.
Also, I think there is a big difference between allowing discrimination (which is only wrong if you belong to a protected class) and requiring discrimination, which is pretty much always wrong.
So its one thing to argue about whether employers should be allowed to discriminate against foreigners (or blacks). There are some good arguments on both sides. But I don't think there are any good arguments in favor of requiring that employers discriminate against foreigners (or blacks).
Yet mysteriously, every country in the world does this (discriminates against foreigners) to some extent, and has for recorded history. If you can't figure out why, perhaps you shouldn't be talking about policy, in the same way you shouldn't delete code you don't understand.
Although I don't necessarily agree with what GP is saying, it seems to be spreading ignorance to say "if you can't figure out why [then I'm not going tell you] and you shouldn't be talking about it". Instead of alluding to a mysterious reason, which you insist one ought to understand to talk about policy, why don't you tell us what the reason is?
Also, I think there is a big difference between allowing discrimination (which is only wrong if you belong to a protected class) and requiring discrimination, which is pretty much always wrong.
So its one thing to argue about whether employers should be allowed to discriminate against foreigners (or blacks). There are some good arguments on both sides. But I don't think there are any good arguments in favor of requiring that employers discriminate against foreigners (or blacks).