There are some ecclesiastical gymnastics required with those other schools, whose sponsoring religions essentially dictate that gay and lesbian relationships should remain non-sexual in nature. And, yet, they find room, to a certain extent, to embrace LGBT individuals, to make them feel accepted and safe, regardless of what the churches' dug-in doctrinal positions are. That embrace may not be as broad and warm as some wish it were, but it reaches far enough for those schools to be in league with other universities with just enough impunity.
There are better reasons to build bridges, even complex ones, than just inclusion in a college sports league, but that kind of connection is significant.