I agree. I think that Joshua's comments serve as an interesting parallel and could very well be an attempt on his part to understand the reason for our concerns.
As for the listserve and other organizations, there are a number of reasons why these things are around. As an African American man, I've been a part of quite a few Black organizations because this country is dominated by White Americans. We are able to discuss matters and concerns that are unique to and largely affect Black professionals. The same would go for homosexuals, particularly in this industry.
Having a listserve or a place to meet could cover a variety of concerns. It would give those interested in joining an outlet to discuss matters that are specific or more likely to concern and/or interest gay rpgers. How to deal with perceptions of homophobia or heterosexism; how to focus role-playing sexuality if that's your thing; how to find fantasy/sci-fi material (integral to D&D) that features homosexual characters. Let's face it; even in the most shallow games, sexuality is going to be an issue. In the vast majority of cases (and I have no problem with this as it makes sense), sexuality will be hetero. But, on occassion, a DM may want to through in something bi or homosexual and it could become an issue. In one game I played, a cleric our party was dealing with always opened the door to his home covered in a robe and nothing else. There was always a woman in the house with him. We knew what was going on, but the characters, focused on other matters, sort of chuckled and let it go. Such encounters, although not integral to the story, reminded that there is a degree of versimilitude in many D&D games. What would have happened, though, if every time the characters went to the house, the cleric was holed up with a guy? I don't think most people would have simply chuckled at it; in fact, I think many reactions (and not necessarily those of my gaming group) would have been poor. A DM concerned about broadening sexuality in his/her game could find an outlet like the one we're discussing very helpful.
On the other hand, it could serve as a vehicle to meet people you wouldn't otherwise expect to meet. To date, I've yet to meet another gaymer. It would be interesting for me to do so for a variety of reasons and one would be for the potential for romance. Even in the larger gay community, role-playing of this sort is sort of looked down upon (yes, even for drag-queens... an irony, I think). The last guy I dated (and still talk to) has absolutely no understanding of my peculiar interest in this stuff and it makes it difficult to have a common ground between the two of us (fantasy and all peripheral elements are important to me). And, even platonic relationships would be nice. It's kind of hard to discuss gay issues with many straight people, even open-minded folks, because you either run into a degree of discomfort or else you become the poster-boy or girl for gay issues (I already spend enough time being the Black guy as it is).
Those are just some of the concerns such a listserv/group would serve.
Appreciate your questions, Joshua.