I'm not in fanfic circles, either, but I do see a lot of that same sort of response whenever any women found a "women-oriented" theater. There's a lot of mocking and rolling-of-eyes, and demands for inclusion, because if excluding women is wrong, so is excluding men.
Huh. Yeah, I can see that.
Not the "if excluding women is wrong, so is excluding men" part. I mean that the phenomenon exists.
When I was briefly in fanfic I happened to stumble into a primarily male group. Now these were good writers...and we would have LOVED it if a woman had decided to write in our little corner. But in perusing other groups I saw a lot of "womens don't get how *we* do our superheroes" and then the same guys would say, in regard to primarily women-attended fanfic groups "YOU GUYS ARE WAY ELITIST YOU ELITIST BEE-YOTCHES YOU! Also, why do you guys always think Batman is boning Clark?"
And, even among the group I was part of there was a fair amount of "We'd love it if a woman, or women, would write with us. On the other hand...I don't understand their fic in other groups."
I, personally, have found that a large portion of the fic I've read in primarily women fic-groups is not to my taste. Not that it's bad...it's just, I dunno..."Not how *I* see [character X]". But I didn't think about that being a gender issue until just now, actually. I just thought I had a narrow vision of [character X] that I was comfortable with because, well...I'm right, the universe is wrong, yadda yadda.
Anyway. My 2/100th of a buck.