probably including me but it seems more about the politics than the culture or the races.

While frontiers have afforded the opportunity to avoid other cultures and races, frontiers have also been great cultural melting pots. In fact the more successful colonies/frontiers have been the melting pot variety. Witness the LDS ongoing controversy. This was an exclusionary society and while the mainstream of that society are good upstanding people, the inevidable schisms resemble inbreeding by their weakness and inadequacy. Alone in the world they would probably destroy each other in a few centuries

I would agree that the conditions we live under today do not promote the healthy exchange of cultural values. We tend to resent other culture when it invades our space and we don't have the luxury of an arms length viewpoint or the time to appreciate how the culture impacts the lives of those who live it.

With dwindling resources and no level playing field we are too busy arguing petty politics and competing for the free lunch to recognize and enjoy the best of multiple cultures.

If we ever expand into the universe there will be trial and error, but in the long run I would bet the successful worlds will be diverse.