If you insist they give up their culture immediately you will be seen as trying to take away their culture. Just like how gun rights advocates perceive attacks on gun culture.
Solidarity is a normal reaction to real or perceived hostility. In history the social pressure to assimilate resulted in immigrant collectivism in order to support each other; Chinatowns, little Italy and a myriad other ethnic enclaves formed partly because of this pressure.
Those who don't learn from history are doomed to repeat it.
And history shows that I'm right. The Irish, Dutch, German, Italian, Polish, Ukranian, Chinese, Japanese, Korean, Vietnamese, Indian, Phillipine and many other immigration waves have come, each met with your attitude, and each has become part of the culture and their children more so.