Welcome to Over50sForum! The site for people over 50 to chat, make friends, discuss, share, and generally be part of something that's fun and friendly :)
There's nothing wrong with a degree of diversity, providing that those who wish to move to a different country are willing to accept the laws and values that the host nation hold are not to be attacked.
There's also not much wrong with expat communities being created, provided that these communities, again, are happy and willing to follow the laws of the land, contribute financially via taxation/work, and not plot against the host nation.