most mexican immigrants despise mexico's political system.
they like the u.s.a. because this country offers them opportunities not allowed to them in mexico.
just as a russian immigrant woman said to me recently, so it is for mexicans: she said, "in just 4 years in america i've achieved the material things that i dreamed of having for my whole life in russia".
you are ignoring the fact that immigrants want to be americans. sure, they may miss the old country, and they may carry on cultural traditions, but that's a normal human reaction. italians of the last century flew the italian flag, etc.
(the few mexicans that spout that racist stuff belong the the universities. no one pays attention to them.)
Sure many do like it here, but you'd be shocked how many abhor life in America. They're here to make the bucks and then off they go to their beloved homeland where they can live high on the hog surrounded by the lifestyle they prefer.
Don't kid yourself. This is fairly well known. You must be hanging out with those rare exceptions.