1.- I doubt this behaviour is intended. I recall Toady saying somewhere (maybe in an AMA) that he had no plans of introducing gay couples any time soon. Although that might have been quite a while ago...
2.- If this really is intended, then make it optional. Period.
3.- I don't know what Toady would do if it is a bug. If he fixes it, he is liable of being stoned to death by the SJWs.
4.- Do you guys really believe the fact that dwarven society doesn't seem to have gender rules is intended? I don't. I think the lack of differentiation between males and females is just a placeholder, so to speak. And if it is really intended, I guess I understand it, as it certainly makes the game much easier and straightforward.
5.-
The argument for "conservative" dwarves [...]
Er, what?
Nobody is discussing homosexuality
per se here. Homosexuality is older than dirt. Attitudes towards it have varied wildly depending on the time, place and situation. The End.
The problem is with gay marriages. I'm sorry to say this, but they
truly are a modern invention. I am simply unable to picture a pre-industrial society imagining and much less accepting the posibility of people of the same sex marrying up. So, no. They add nothing to the game. Just make them optional.
In fact, I dare you guys to find a single pre-industrial society which allowed and celebrated gay marriages.
Well, that was that. Sorry for being annoying. Gotta get my helmet...