Not sure whether to vote up, as I refer to women as females in order to avoid being sexist, but I can see this already has many upvotes (I wonder what proportion of those upvotes were by women, though). In my experience, most of the prejudiced sayings/memes are directed at 'women', not at 'females', which is why 'women' feels more sexist to me. (although any reference to sex or gender that is not obviously necessary also feels sexist, so I normally leave any such references out entirely whenever possible.)

Why do you think it is that it can come across as either autistic or sexist?

FWIW I live in South Australia, in case this turns out to be a cultural thing.