"Women didn't like it and left" is certainly an interesting interpretation of the systemic exclusion of women from a field when it transitions from low-prestige manual work to high-prestige intellectual work.
Given now ~two decades of affirmative action for women getting into technology, and many high-status "professional industries" now dominated by women, the idea that the best explanation of this ratio is 70s/80s culture is implausible.
What we have seen, instead, is that as women are more free to choose professions the percentage of women's involvement drops.