LJ was my first exposure to the idea of "gendered" fandoms as well. Prior to that, I was at the Bronze for a couple years, and then Mod of ATPo for the next four years, at which point we expanded ourselves over to LJ.

I'm realizing how atypical and sheltered ATPo was. We were mixed gender, and gender was never an issue. People were, for the most part, polite and fun-loving, fan fic was barely a blip on the monitor compared to discussion and essay. We had our melt-downs and kerfuffles (the Spike-Angel wars, anyone?) and trolls, but we rode those out and survived.

I never frequented any other boards (including LJ) during the height of the ATPo era (2000-2003), and the way fandom was expressed on LJ came across as very weird. But LJ's format, allowing communities to spring up over every little quirk, seems to lend itself to people dividing themselves up along gender lines, character- and ship-preference lines, and any other lines. Which is good if you have a fandom quirk and want to meet like-minded souls (I didn't know many Connor fans until I moved over here), but it's a mixed blessing.