I am not, for one second, advocating pos disc. And no I don't think all airlines are anti-gay, but I have personally met many pilot's that are, (and many that aren't). Company culture, which is what I think is at the heart of the matter, can bring out the worst in people, if not carefully monitored. I would personally hate to sit in a cockpit on a long sector, next to a w***ker who spends the entire flight spouting homophobia, and it does happen.
I also agree that it shouldn't even be an issue, I bet the person who initiated this thread is laughing his/her tits off at the ensuing debate, but it does become an issue when individuals want to offer their partners travel concessions and can't, or want to take them to company do's but don't feel that they can. Sorry if you think I'm tarring the whole industry with the same brush, I'm not, but the truth is that some companies are better than others in not discriminating -vely.