> There are people in this comment thread claiming that work visa are really awful and restrictive.
I'm not sure about their experience and my knowledge is 3rd party, still, YMMV.
> Is an immigration preference people of certain nationalities fair?
Not really, but no country does this fairly, and they're not wrong (within a limit). Key word: immigration. Is it fair that Canadians don't need a visa to visit the US but Mexicans do? No, but they're not wrong and Mexico is free to require a visa as well.
> Can I assume you agree with Trumps immigration bans by any chance?
The travel ban, not the immigration ban. And no, I don't agree that people with a valid visa (or even permanent residents, which was what the Supreme Court shot down first) shouldn't be allowed to visit (unless there's a specific issue).