Personally, I don't think they aimed high enough. Alan Scott is (though one of my favorite characters) a bit player on a non-mainstream stage. That's hardly the "iconic" character DC promised to deliver.
Understand that I think Robinson's a crappy writer who wouldn't know heroism if someone saved him from a burning building and left the arsonist tied up outside the police precinct, but he also has a point: Why not? People are gay, and sometimes even married people realize (or decide, or whatever) that they are. If it's not written as a punishment for the character and if the character isn't satirical, it's the same as revealing that he's Jewish, a Trekkie, or a socialist.
That's where the homophobia accusation comes from: Asking why it has to happen implies that it damages the character or it's a handicap of some sort. Sorry, no. It's worse than a handicap, because people are happy with a wheel-chaired Barbara Gordon or a blind Matt Murdock.
(It's also worth pointing out--and I realize this undercuts the "revelation" aspect, which is unfortunate, because it could be a good story--that this is a reboot, and therefore a new character, unsaddled with decades of continuity. Anybody worried that Alan Scott is "being molested," as Alex Ross allegedly said about Obsidian, is overlooking that they haven't said a thing about "your" version of the character.)
As to why? The same reason Clark Kent is traditionally a nebbish who wears glasses: Comics are generally something for society's fringes to look at and say, OK, maybe this isn't something wrong with me. In the Superman case, it's that maybe my being bookish and meek doesn't prevent me from going out into the world to change things for the better. In this case, it's that being gay doesn't mean a life in the closet, limp-wrist jokes, and people calling you the devil until you commit suicide or win a Tony Award.
What I find offensive about this (and not being gay, I may not have the proper perspective, here) is that it's such a minor character (hardly a role-model for closeted readers to identify with or something to convince homophobes that maybe--just maybe--they're being petty), it's so late in the game to be worth bothering at that level (for both comics and gay people), and you're right, it's structured so that criticism (probably even mine) is guaranteed to be viewed as homophobia, even if the character is portrayed as a horrible stereotype.
I'm also more than a bit put off by the "principle" Robinson apparently used that, since Obsidian was gay, and Alan is too young to have kids, well, "the gay" must go somewhere. Idiot.
Personally, I would have gone for Hal Jordan. You know, the Green Lantern that people saw in the movies and stars in two of DC's flagship titles. That would be a step worth taking (and be far better than the fiasco of John Stewart bumping Hal out of the book, thirty or so years back), whereas this reeks of cowardice, both in its action ("we need to do something so people think we're relevant") and its inaction.
