(We are getting more and more OT) Cultural diversity? Well ... the problem that IMHO most of the prophets of cultural diversity fail to see is that it's supposed to be the cultures that compete, not the individuals. Which the current everythig's-equal multiculturalism prevents. First by banning any competition and second by attempting to create a heterogenous at the smallest scale, but homogenous at the larger one eintopf. Yeah, each of the families in the building comes from a different culture, great isn't it? Well not su much, if you have the very same mix in the next building, the next town, city, country, continent.

The ideal multicultural world would be more homogenous than anything the world had ever known. It used to work the way that you had many more or less homogenized societies that were competing. Each of them more or less different than the others, each of them having some time and space to prove its worth, take from the other ones things that worked (within limits of what change that culture could accept) and adapting to the changing world. If you destroy this by mixing eveything together, there will be no cultures left to compete, no societies that work according to different rules and could take over when another societies loose the direction.

And I'd like to point all that feel allured by the noble words about caring for those deprived versus the lowly economic goals at the examples of results of such ideologies. You may think that you'll do better next time than Soviet Union, China at the times of "culture revolution" and later, Albania, Romania, North Corea, Cuba, Vietnam or Cambodia (to name just a few) did. Maybe you would, but I would not bet on that.