Monoculturism at work.
That's overstated. Female genital mutilation within a tribe in Africa is also monoculturalism, inasmuch as foreign interests and influence do not play any part in the practice. What happened in Iceland is bigger than merely that.
You’re on to something there.
In a single culture, it’s harder for the elites to pit groups against each other instead of letting them unite against the elites.
This very well could be one of the major reasons the left pushes “multiculturalism”. Of course, there’s that reason, and their visceral hatred for Christianity. But I digress.