I think I know where some of it comes from.
And apologies my head isn't working right today so this might not make sense.
For a while in the 70s, and 80s even into the 90s those women who chose to go into the 'male ' fields of work were in a difficult position.
In an era of being accused of taking men's jobs, that we should be at home with the kids, that women are frail little things, in order to prove women deserved those jobs just as much as men we had to do what the men did.
So we carried full hods of bricks up ladders, we used tools and equipment designed solely for men, we knackered our bodies whilst not complaining but stating we were just as good as men and just as capable.
For some of us having women in these fields be seen as normal was more important than the safety aspects. We couldn't complain about the working conditions, and we put up with a lot of shit that we shouldn't have had to in order for the next generation to have an easier time of things.
At the same time there was another load of women coming at it from a different angle trying to ensure the women in the workplace weren't injured due to differences in our bodies that meant we weren't actually able to do everything in exactly the same way as men did.
It took a while for all this to merge into accepting that women can do all the jobs that men do, but that we aren't actually men from a physical point of view.
So there were women shouting loudly that men and women are exactly the same. I was one of them. Of course i didn't believe it, but I had to say it and act it as that was my part in the march to equality. I was the female doing the man's job, and doing it just as well as he did. My body has paid the price.
I think younger women may see the past more as a straight line of women got this right then and that right later etc. But so much was going on at the same time. And women had to do a lot of things that we really shouldn't have had to go get to where we are today. Literal blood sweat and tears.
Of course right now I can't help but wonder why I bloody bothered!
I think there is a fair bit of cherry picking going on in MRAs mind as to how women came to have supposed equality in the work place.