I too have noticed many Aspies appear androgenous, and not just physically. I suspect there is less sexual dimorphism among autistic individuals, which is an overarching reason for their relative lack of progency. Unknown.
However, I am an enigma in that I am very physically feminine - extremely so, in fact. I wear make-up, jewelry, love 'girly' clothes, etc. Plus, my features are overtly feminine. I am considered very pretty by outsiders. And I am definitely heterosexual with a healthy sex drive.
But, my mind, cognitively, is very analytical. As is my writing style (and handwriting!).....often when another whom I have never met reads my work (writing, formulating, art, etc) they'll just 'naturally' say, "He says......" Very strange! For acquaintances, co-workers, etc I tend to prefer men (with some exceptions). At the risk of seeming sexist, men truly do think more analytically. I am likewise. I am mechanically inclined too.
I think you're observation has merit and is not new either - there is a higher propensity for homosexuality and asexuality among the autistic population. There is a sexual correlation, but the overlap is murky.
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The ones who say “You can’t” and “You won’t” are probably the ones scared that you will. - Unknown