Why on earth would it matter to these arguments whether there are intersex people?
Look. Race is an obvious place where there is much MORE of a spectrum than sex. Does that mean "queering" race by parodying blackness or declaring it as a white person would be okay? Disability's a spectrum, too. Are disability cheats just "queering" an oppressive system?
Everyone's acting like the fact that scientifically we could divide people in these other ways matters. For 99.9999% of human history, the science of reproduction was so poorly understood that women were thought to be only vessels, rather than contributors of reproductive material, in most cultures.
The reason that oppression divides the sexes into a binary is that for the huge, huge majority of human history, you've needed a vagina when you were born to get pregnant, and a penis when you were born to impregnate someone. It frankly didn't matter to the people using this system whether these classifications left some people out in the cold, it wasn't designed to grant wishes.
Since infertility was very poorly understood, the idea of "well, then, women who aren't fertile wouldn't be oppressed" is stupid. The mechanics of infertility are still difficult to understand, and supposedly infertile women conceive with stunning regularity.
Oppressions can only develop in the context of people's actual knowledge. The single biggest clue people had to whether someone was the impregnable or impregnating group of humans was their genitalia. The understanding of human sexual development, biochemistry and anatomy developed in the last 20-30 years bears literally no relevance to the historical oppression of female people, because historical people did not know how to perform DNA tests or check hormone levels. They only knew how to check what was between the legs.
People can talk all they want about the utopian society they'd like, where it's decided differently, and that's fine. But when we're talking about combating the current effects of thousands of years of historical oppression, it seems like an incredibly handwavey, mansplainy thing for people to say "oh, you just don't understand the SCIENCE that makes all your oppression irrelevant."
-- AbortionFairyGodmother (I also run a blog at culturallyboundgender.wordpress.com, which was linked in this thread)