Ultimately, what you have to ask yourself is what multiculturalism has delivered after twenty years. The answer is basically an anti-assimilation sentiment in the mainstream which has essentially fed social dislocation and identity politics.
For my part, I was a supporter of the idea that Americans all had lost identities that were sacrificed to assimilation into the mainstream - that it was a bad idea that Italian Americans no longer spoke Italian. But I have given up that premise. National identity and the national culture are always in need of repair and maintenance. And it is my opinion that what we need more than the relative autonomy of various cultural imperatives, is a social cohesion that defeats identity politics.
In short, I am against that thing I call 'radical autonomy'. I see radical autonomy as any collective group identity that seeks national recognition outside of the political process. That's about as deeply as I want to get into that.
Multiculturalism that demands its own channel of information to and from the mainstream is destructive.
'Diversity' is a meaningless term in today's society. It means race. It means gender. It means sexual preference. It means giving political meaning to identity absent any real difference in thought. It means giving preference to the body over the mind.
PC is the language of 'diversity' and multiculturalism. It is nothing more or less than Orwellian.