I don't honestly think it's as much of a matter of making fun as it is to GET ATTENTION from everyone else. I have no issues with people having homosexual characters, bi or what they might want their character as however, like this post was about and people having "Lesbian" "Gay" "Bi" Etc in their very name for the character is only to seek attention. If you were serious with your character it's just to modify your bio and post in there what orientation the character you play has.
Though the simplicity of a place like bonfire usually have a more basic and straight approach about most things, sometimes for the better, sometimes for the worse, in this case though I personally don't approve of users having their characters sexual orientation in their names and usually is players/users that might need a second look to see what they are up to.
It seems to have periods when these type of names comes up because at times it can be rather empty of them for months and then one week you see them roaming around a bit here and there. Without a question though, if a few users play around as a gay character others take their chance and join in as well, and it's not too uncommon that you see these people group up like they were some sort of pride or pack, some even take it to the next level and make "Gay lovers" group or what they might seem like a good idea at the moment. Now don't get me wrong, if you support all love that's fine and everything but some people must just create such a scene about things and not everyone approve of this and it can at times cause drama or inappropriate moments in the game that literary needs cleaning up. I really do believe it's not that hard to just write in your bio stating the characters orientation rather than changing it's name.
The only reason to change ones name would be to be as you said above, to make fun of homosexual people... Or, wanting attention for various reasons and many of these reasons usually lead to something worse. Though I try not to judge before knowing but these users are probably very young and do not quite understand the whole picture with homosexuality(no I'm not speaking of the malexmale or femalexfemale, I speak of how the so called society picture this and how users opinions and views vary), or that someone is old enough and use FeralHeart to look for someone like it was a plain dating site, the thing is if people want to get mates with their characters I can easily understand, but the sexual orientation being so important that it must be in the character name I think is a very questionable thing and judging by what I've seen and how people behave when they actually do have these names, it's what I can see from it.