Because obviously, the things that represent incomprehensible, corrupting influences are people that don't look like you, people that don't act like you, and people that don't think like you.
Amazing worldbuilding chief, what's your next big idea, eugenics? OH WAIT
hot takes about writing
There are so many cool ways to represent a fear of the unknowable, and of course Lovecraft picks racism, xenophobia, and ableism.