I told myself I was going to cut down on forum posts but oh well... I shall contribute to clarification once again.
It's not currently brought up due to the past wall against it. It's not that the Devs have a problem with it per se, but with the already large laundry list of issues they have, taking on controversial topics comes in at the bottom of the list. This is basically because implementing it could cause an even bigger firestorm than not doing it caused. Should you go looking for the old topics on it, take your armor...
Also note that most of the gay characters in the game are fairly new. I distinctly remember the time before lesbian characters became common. In fact, I would go so far as to say that Lhaa influenced a lot more female characters being lesbians. Not that she was the first, but it didn't become quite as common until after her, in my opinion. Also, gay male characters are still quite rare. Thus, while it was argued for every now and again in the past, there probably wasn't even enough gay characters to merit changing the code.