We can't say systemic sexism caused the crash in enrollment, which happened very suddenly. It is certainly a factor, and probably a bigger factor over time explaining sustained low enrollment.
A snap drop in enrollment is more likely due to a shift in the culture somewhere. Someone pointed out that the game market crashed the year prior, that was probably a factor. Was it Reagan? Was it the number of high profile movies in which nerds were stereotyped?
It is hard to say and a very interesting question.
See: https://cdn.arstechnica.net/articles/culture/total-share.med...
Prior to anyone having a computer, your suitability for getting in CS would be the math classes you took, which had some "equality of access".
Once the sales boom happened, anyone with a computer probably had a large advantage to anyone that did not.
If that was the driver, though, it would imply some pattern where these computers were less available, or less appealing, to young women.
I don't know. Her examples are unconvincing. That they maybe advertised to girls more could just as easily mean, the boys are already buying them so let's focus on the untapped market.
The common theory around early exposure seems plausible to me. [ADDED: Together with the fact that it's supposed to be this all consuming thing.] I've read equally well-written articles by woman nodding their heads. https://www.bloomberg.com/view/articles/2017-08-09/as-a-woma...
Unis could deal with it to a degree with intro to computing everything but CS has emerged as an almost unique major (music is certainly another) where showing up at college saying you want to try this computer thing is considered odd.
No one expects a chemical engineer to have done much more than really enjoyed their high school chemistry class. EDIT for clarity: Demonstrated "passion" for chemistry isn't really a pre-req.
1970s:
20,000 "nerds" with equal gender distribution
M: 10,000 (50%)
W: 10,000 (50%)
1990s:
200,000 "nerds" with equal gender distribution + 800,000 men primarily focused on money
M: 900,000 (90%)
W: 100,000 (10%)
Edit: this theory doesn't deny the argument that CS as a field became particularly uninviting to women over this time period as well, but the causality goes: men enter field for the $ => increasingly skewed gender ratio => male-centric culture develops => even women "nerds" stop joining because environment has become unfamiliar at best and hostile at worst
I've heard this from a number of other women: an influential, well respected person promoted a divisive opinion among teens for a long time. The effect was subtle and perhaps unintentional, but pervasive; young women decided they were not smart enough or strong enough to work in the field they wanted.
This illustrates to me how important it is to send the right message to kids. Subtle divisiveness is dangerous among kids and teens.