Might it be helpful to remind ourselves of some 101 stuff here? I go back to this site again and again, to hone and refine what I'm thinking, and it might be clarifying for this debate, specially since female separatism has been compared to white supremacy.
"What is sexism?"
Sexism is a 'matter of opinion''
"Aren't feminists just sexist against men?"
I find the middle link particularly helpful, and recite it to people a lot (they love it!) "Institutionalized misogyny, like any endemic prejudice (racism, homophobia, ageism, ableism, sizism, etc.) should be viewed as a system, with rules and laws governing its existence?although, by virtue of cultural indoctrination, they generally aren't obvious unless one makes an effort to see them.
The patriarchy is very like the Matrix, in that it is a false construct laid over the top of a reality, that makes things look very different. Viewing the same thing while fully and uncritically socialized into the patriarchy and while cognizant of its falsity creates two very different pictures."
Female separatism is comparable to black people seeking safe spaces away from white people, not to white supremacist separatists. This is because sexism is predjudice + systematic oppression. Sexism/discrimination can be an an individual act, but the systematizing of it over thousands of years = patriarchy.