In the latter half of the '80s, MIT changed their admission criteria to get a larger percentage of women undergraduates in incoming classes. This cohort did not have the same level of "STEM advanced placement" prep classes as before and the grind/pace/atmosphere of the freshman filter classes changed; many faculty were not happy about it, as I was told by female students from that time period. I don't doubt that similar changes took place elsewhere.
I'm not saying this was not an improvement, simply that it meshes with your timeline and sheds a different specturm of light on what you are pointing out. (to put it another way, there were traditionally many fewer women who wore pocket protectors and carried sliderules, but yes they were very much a part of the community)