I've never understood the objection to an organization or business that restricts its patrons based on a given criteria.
The right of association is another right lost to the PC crowd, although not totally. The Congressional Black Caucus can exclude whites and blacks who are not Demoncrats. White Power clubs get banned while Black Power clubs get student body fees and official sanction. Women's Studies are fine, while male athletics have to share 'equally' with female, or be coed. And on and on.