Clearly the arguments here are a rehashing of two different versions of feminist action - and both have been successful in winning rights and opportunities for women in the Western world. Which you prefer often comes down to a philosophical difference about "essentialism" - do you believe that women are essentially different than men? As that question is unresolvable on this list, I suggest we turn to practical questions to resolve this issue.
1) Since we cannot know contributors' sex for certain (and thus predict their reactions based on any kind of essentialist philosophy), I am unconvinced that forking the list would be effective in the way that such groups have been for the feminist movement already. 2) Since the number of people in the Wikipedia community who want to work on this problem is small, we should work together until such time as multiple groups are even feasible. Too much fracturing diffuses the impact we can make. 3) Many women react in ways that are just as sexist as men. Some of the most damaging sexism I have seen on Wikipedia came from female editors. We should not exclude male voices based on the assumption that they could be sexist but allow any female voice.
My two cents.
Adrianne (User:Awadewit)