To be Catholic in America is to belong to different camps. Some of us act like Pentecostals, some think it's eternally 1972, others have left the battlefield altogether and went to SSPX or became sedevatcantists. Others, perhaps the majority stayed but decided to have no part in the parish life other than toss a buck in the collection basket once a week. Those who send their kids to the parish school are heavily involved in the school but inadvertently make the parishioners who don't have kids feel second class.
The Hispanics have their own masses and groups and don't interact with the rest of the parish at all. They aren't encouraged to either. From what I've seen this is the way most of the non Hispanic parishioners like it and they go to sometimes comic lengths to avoid being around while the Spanish Mass or rosary is going on. The Koreans and Vietnamese Catholics are given their own parishes completely. Black Catholics either go to their own parishes or often times find themselves isolated at other parishes.
It could be argued that the Church in America has always accommodated ethic parishes---- I agree but look how it turned out. Those lovely old churches in the city that were all Polish or German or Irish emptied out in the 60s when desegregation came along those folks ran to the suburbs. Those churches are closed or have Mass only in the morning and lunch time for folks who come into the city to work. Isolation doesn't help the church and when the neighborhood changes things get greasy. I don't know what the answer is but this separatism just doesn't seem right.