What city do you live in, exactly?

I live in Los Angeles - one of several metropolises that I've lived in on several continents - and the vast majority of second and third generation immigrants I've met have had no trouble assimilating into their host culture. As an immigrant, in fact, I have struggled to find any zero or first generation immigrants that do not bemoan that their offspring are completely detached from their culture. They consider themselves lucky if their grandkids still speak their "native" tongue at a primary school level.

What I have seen everywhere, however, is a lot of small minded people who are only capable of differentiating each other by superficial ethnic stereotypes, dominated by skin color and religion. They've always got "plenty of evidence" that they "will not list here due to it being tangential and often mistaken for malice."

My apologies if I've got the wrong impression, but perhaps your understanding and methods of "assimilation" are fundamentally flawed.