Dude's come on too strong in gaming communities, which leads to most girls keeping low profiles or just avoiding them completely. Also, without coming off sexist, I think there's a tendency for RuneScape to appeal more socially and aesthetically to girls, rather than the typically male "Noxpwastegrindallday420' mind set - considering our server has low player count, and it's hard to make your character look cool or cute with our relatively limited cosmetic item pool (nearly no rares, no skill capes, no colored robes, misc. quest items, etc.), there isn't much to draw in many female players, or to keep them around.
Just an opinion, of course.