@pearl1 I've read these studies "proving" that women are aroused by seeing women having sex. My best guess is that they were shown porn, which, as we all know, has absolutely nothing to do with lesbian sex, given that the women taking part in it are obviously straight women looking disgusted at each other at all times - but then, again, all straight porn is made for straight guys.
Back on topic: I find the webcomic community in general to be dominated by extremely vocal youngsters in general, because they need to build bridges and find their own place in the world, because they are still trying to understand who they are, and because many readers are young. Older people tend to worry much less about that, because they either already have some established job/fanbase and/or they are completely baffled by the webcomic community and/or they just don't have time to "waste" on this (real life is much better). Mind you, this is a simple conclusion from personal experience. You should make a serious study to figure out how things work here, especially given that people come and go. One thing I did notice is that the community has slowed down forum activity immensely over the past year or so. It was nearly impossible to follow a single thread, for how intensely people posted. I don't know exactly why (I have my own theories, of course), but I think it's a normal part of all forums, and it's something to be kept in mind - less activity means a less clear picture of who is part of the community, silently or vocally, in the end.
As for LGBT people, I belong to the L, but I have absolutely nothing in common with the (mostly young) people who declare themselves queer. I don't understand all this aromantic/asexual/demisexuul/agender/trigendered/boltgendered community, it makes absolutely no sense to me, but I understand it's currently a big and loud thing in certain quarters, and it's spilled over into the webcomic world.
In conclusion: you are only hearing vocal people in the forum. As for who they are, you need to do a real study, and not just look at anecdotal evidence.