>I don't follow this argument. Levels of sexism in the 60s and 70s are irrelevant to decisions that women are making in the present.

The argument is not about that.

It's that "Those very sexist 60s/70s fields still had a lot of women going in, more than women in IT today. If women could go into those very sexist fields then, it's not sexism that keeps them out of IT today".

This is ridiculous, changes in the 60's led to a more gender balanced field, which obviously made for less sexism. Pretending that root causes don't matter isn't helping your case.

Aren't you then acknowledging that as a result, tech now is more sexist than law and medicine?

If so, I can't see where we substantially disagree. As I've repeatedly said, I make no claims about why the gender balance shifted in law and medicine in the 60s. You appeared to suggest that this had nothing to do with levels of sexism. I'm skeptical of that claim (broader societal attitudes are important too, not just the sexism level of lawyers and doctors vs. the sexism level of scientists and engineers), but it's not as if either of us has actually researched this in detail.

The key point is that tech now is disproportionately sexist, as you appear to acknowledge.