It's a pretty big deal. Even if he is an older FA, he's still technically the first active athlete in one of the major sports to come out. No other NBA/MLB/NFL/NHL player with aspirations of continuing playing next season has done so.
He knew he'd get a lot of attention, both very supportive and very ugly coming his way now. It's pretty ****ed up, in my opinion, to immediately disparage a guy doing something nobody else in the history of these major sports has had the balls to do. At the very least, read his well-written, thoughtful article explaining his decision. Good for him.