Diversity is a buzzword used by the liberal media
Buzz word. Liberal media. That makes me giggle.
I mean let's look at it for a second. On a basic genetic level, Diversity is fairly essential to prevent damage occurring from inbreeding.
I suspect the same is true on a cognitive level too. Your own thoughts can become narrow and restricted if you shut yourself off from the diverse opinions of the full spectrum of human experience. Narrow mindedness and the fears it brings are as likely bad for mental health as a narrow gene pool.
It could well be the case that those with narrow minds and limited genetic pools are in fact quite sick.
Purely speculation though.