When those issues existed they weren't past, they were present. As soon as the barriers are removed the excuse becomes invalid and disempowering.
*Refers to example of Bob in the workplace.
"The architects of civilization" may be long gone, but we still live in the civilization that they built. A lot of barriers we might be sensible enough to choose not to build today are still set like concrete.
My sister was a very early on feminist. One time I managed to get an argument through to her. It went like this.
She decided, very early on, that the 'get married and be a supported housewife' plan was not for her, and would never be for her, and was anathema to her. There are two important things that her decision did not change. It did not change that other girls her age might not have seen such a choice as anathema, of even 'not for them.' As a choice, it
was available no matter how wrong it might be to force anyone to take that choice. (Keep in mind that I am old and my sister is older. Her choice was by far the more 'outlandish' in her peer group, and to parents of her peers, as well as our own, such thinking was borderline dangerous.) So the first important thing was to not write off everyone who made that choice as a poor benighted victim of oppression.
The second important thing was that no matter how supportive I, or some other guy, might be in regards to gender equity, I grew up without that choice. When I could no longer stand our parents, I would either get a job or I would starve, period. Not that I had any more desire to be a housewife than my sister did. But there is a difference between a choice deemed horrible so not taken, and having no choice to be made. That difference made growing up male much different than growing up female, in our era. The resolution of that difference, unfortunately, seems to be the creation of "two incomes necessary for survival," so now no one has that choice, rather than some sort of expanded freedom. Bummer.
Anyway, the relevance is that even in those days there was no lack of "woman's right to work." Heck, our own mother who was appalled at my sister pretty much always had a job. The barrier had theoretically been removed a couple of decades before. Society did not magically change overnight.