> However, having people of similar cultural/linguistic backgrounds helps a lot with communication, both inter-personal and for business.

It helps on communication, definitely - but it is a detriment against "fresh ideas" or when testing out new products.

so tired of the self-hating/self-loathing label when someone criticises their own nationality/ethnicity

You can't make yourself look less racist by pointing to other racist cultures (while describing with details your own racist behavior).