I think the reason is the first migrants were pure economic migrants who want the jobs, security but not the country as such.

America, probably because of its heritage, is very big on drumming into everyone they are Americans. Salute the flag, morning statement at school and also when becoming a citizen. Here there is none of that. America us undoubtedly changing with influxes of new people, but these are adding to the core rather than choosing enclaves.