More recent fears over men in proximity to kids probably reinforces this.
I've certainly heard the theory you suggest and it does seem to make sense. Perhaps the data doesn't show that because as smart women have 'left' teaching they've been backfilled by the additional women joining the workforce that didn't used to be there?
Interesting questions around the massively skewed jobs.
What happens to the structure of society when a larger fraction of intelligent people have access to higher education, the ability to easily relocate, and a financial incentive to work in finance, science, engineering, and applied-academia?
How does that impact legislative and executive politics, community groups, and education (direct and educating the educators)?
[0] https://www.census.gov/library/visualizations/2016/comm/cb16...