I don't think people are that different wherever they are.
I think if you'd lived in South Africa in the '80s and Los Angeles in the '90s, you might have a greater appreciation for the differences in human behavior. I'll never understand people who believe human nature is some single, fixed thing. Human nature encompasses everything from Gandhi to Hitler.
I think there would be very strong resistance to integration of an alien species unless there was a clear benefit for humanity and even then it would be a big ask for most people.
And again, if you remembered Alien Nation
at all, you would remember that there was
very strong resistance from many quarters of the populace. The government had belatedly allowed the Newcomers to integrate, but a large part of the human population resisted it fiercely -- just as many white Americans resisted it (and, alas, still do in some quarters) when the government passed laws ending discrimination and segregation toward black Americans. Seriously, the whole series was about
those racial tensions and the Newcomers' struggle against them.
A more likely scenario would be to put them in concentration camps and hope that someone else will deal with it. Either that or put them in self-governing reservations in the back end of nowhere.
Which is what was
done initially. According to the original movie, the Newcomers were quarantined for three years before finally being allowed out into society.