Cultural assimilation of one group by another has gone on for thousands of years and all over the globe. Sometimes the process is gradual and voluntary. Sometimes colonialization and conquest is involved.
There is nothing necessarily wrong or right about a minority group assimilating into the majority culture. But there is something wrong is how some people go about it. Some individuals carry a degree of self-hatred and denial of their origins.
Others go further by assumingthat openly rejecting, if not outright attacking, fellow minorities would ingratiate themselves with their "mainstream" friends.
Some see majority acceptance as a "limited commodity" for which they must compete against other minorities to gain. As a result, even 'peaceful', 'voluntary' assimilation can have a negative fall out. THe end result is minorities mistreating each other.