It does seem that females make up majority of the target for both yaoi and yuri, although I'd deign to say that, ironically, my experiences with the yuri fandom are much, much less "rabid" than the yaoi side. I vastly prefer yuri, although my sexuality tends to lean in the gynesexual persuasion, something akin to loving women, including transwomen. I'm not sure if it's necessarily a fetish for women or what, but I don't really mind either way. Femslash is my life, and I have resigned to this fact.