I just think that it's within that person's rights to say that they feel that their experience is different than that of gay women.

Agreed, but I don't think that particular poster was doing that, because in some places, he didn't qualify "gay" with male; it was just "women don't understand the gay experience". And maybe if I haven't seen that assumption so often, that gay = men and that lesbians don't exist, I'd be less annoyed.