I think the threshold for too much diversity is high. Going to college exposed me to a lot of different people and cultures. Despite a few misunderstandings it seemed great for everyone.
The only real downside I can see is if immigrants become isolated in enclaves or the 'natives' are xenophobic. (Ultimately we're all immigrants unless you belong to a demographic that evolved where you live today.)
The only real downside I can see is if immigrants become isolated in enclaves or the 'natives' are xenophobic. (Ultimately we're all immigrants unless you belong to a demographic that evolved where you live today.)