Nobody ever says this about mediocre white women, or any POC of any gender
Seems to me that these people want to date people of high social status/privilege in society - and due to mediocre white men’s complete lack of any highly positive qualities - by virtue of being “mediocre” - can more easily be stripped back to only being viewed as white and a man as the sole standing “positive qualities”, making them a more pure symbol of status/privilege
Doesn’t have to be this exact phrase. Mediocre white men, medium ugly, slightly ugly. All the same
I like your theory though, that’s really good