Earlier quoted context omitted.
> propagate itself on its own merits You're right that not all traditions are worth preserving, but Darwinism isn't the best way to choose which traditions are worth preserving. The problem is that ability to propagate does not imply merit. If you put a bad guy and a good guy in a room together, sometimes the bad guy just beats up the good guy, and you realize that you shouldn't have put them together. This is the sa…
Some people in a small, homogeneous country might feel hat their traditions are worth preserving. Theirs is the voice that matters. You can't hold a global referendum on that, because their votes would be vastly outnumbered by those who don't care or who want to trample on them and help themselves to their resources or whatever.
Eh, that's just cultural conservatism, the rallying cry of racists and skinheads the world over. Are you also afraid they might marry your women and corrupt your children?
It's really quite fascinating... Europe, for generations, colonized the rest of the world, imposing their own cultures on indigenous populations (and I say that as a Canadian... we spent 100 years trying to wipe out our own indigenous population).
Now that the tables are turning and Europeans are struggling with immigration into their own countries, violent xenophobia is springing up like a vile weed.
Ironic, really.
Now, that's not to say large, unintegrated (and note, I say unintegrated, not unassimilated... those are different things) immigrant populations aren't a challenge. They most definitely are. Any isolated population, particularly if they're disconnected from government, law enforcement, or the social safety net, are a difficult challenge (my own city struggles with pockets of unintegrated north african immigrant populations, for example). But it's a challenge xenophobic europeans created for themselves, by allowing these immigrant populations to remain isolated in the first place... ironically, in part specifically because of that very xenophobia.