People often make reference to a time when programmers were predominantly women, say roughly the 50s-70s but I don't get the impression most younger people personally know someone whose career was largely during that era.

I do/did, and the reason she ended up as a programmer was because she wasn't considered for an engineering program (because they already had a woman studying engineering) and had to take a math scholarship instead.

If we want to continue to live in a world where women can become engineers, and managers, and CEOs, then some of the talented people who were forced to become programmers in earlier days are going to be diverted.