And if their use of scare quotes is to express doubt that "overrepresentation" is a good justification for discrimination, then I agree.
I also don't believe gay people are underrepresented in higher education, relative to their overall population in the United States, so I don't find that part of your argument compelling. I've found this quote with a brief Google search,
"The three surveys of American adults consistently indicated that gay men are far more likely than straight men to have graduated from high school or college, with just over half of gay men having earned a college degree, compared with about 35 percent of straight men. Some 6 percent of gay men have a Ph.D., J.D. or M.D. — a rate 50 percent higher than that of straight men."
From this article: https://www.nbcnews.com/nbc-out/out-news/straight-men-face-e...