Care to provide an example of sexism to back-up your rant?
Also, the number of women historically majoring in CS dropped off significantly in the 1980s, when 1. Video gaming culture started to take off and 2. Hardware (something seen as more masculine) started to be emphasized more often. Like, programming historically was something women with math and CS degrees did, then I think there was a greater influence of hardware and tinkering with your hands that was part of being in tech. Stuff that is traditionally seen as more masculine.
The DSM-IV (1994) quotes a prevalence of roughly 1 in 30,000 assigned males and 1 in 100,000 assigned females seek sex reassignment surgery in the USA.
So there's a 3x factor feeding into that.