Oh, but it does. There are few better tools for an entrenched elite to use to deny majority interests in the pursuit of social control. You're right, it doesn't serve any national interest. They aren't after any national interest.
The idea behind multiculturalism is that someone gets to make special sets of rules for each separate class and dispense largesse to the degree that those classes perpetuate their control. It's really nice to be that someone or that someone's favored class. It sucks to be everyone else, especially the majority "oppressors".
Never heard the mention of "oppressors" and "colonialists" used much before Obama. Wonder Why? . .