I agree with that, I am pro-cultural diversity and cosmopolitanism. Saw that it is in cosmopolitan areas that science made the best progress.
Not for relativism, nonetheless. I think cultures (American culture, French culture, etc.) should be freely approached with a critical eye.
NB: Culture is not race, first of all, because race does not exist, and second because cultures are just ideas, not peoples. So when critically assessing a culture, we are not, or at least we should not be perceived as, lacking respect to anybody.