To be fair, the use of "nobody" in that sentence is a bit over-generalizing but isn't the sentiment of the sentence quite clear? If a group is a very homogeneous, outsiders might think that they're not welcome/ have lower chances of getting in.
I don't have any scientific proof to back up that claim but I can certainly relate from personal experience without belonging to any minority.
I think calling that "incredibly racist" and implying
Cthulhu_ is just "echoing" something from their circles is quite out of line. In the future maybe you could just point out what you think is wrong with the wording instead of attacking OP personally.
Also: There are things in this world which are "incredibly racist", which is beyond horrible. But do Cthulhu_'s remarks really belong into that category?