So, essentially, ,most women who worked for 12 years before the Equal Pay Act in 1970 are hugely worse paid over their careers than men, and than the tiny number of women who graduated with degrees in 1958.
This, apparently, is all feminism's fault, cos you know everyone really tried hard to exploit the vast majority of women. The nice patriarchial system just employed them on shit wages and made it perfectly ok to pay them less than men ... that hardly compares to the evil of feminism whereby some small number of women (the hussies!) made it and got paid substantially more than most women. Let's search out that tiny minority and burn them, right?
This article is one level up from the sort of idiocy where people believe the moon landings were faked. Except I expect it isn't idiocy really, it's someone deliberately taking a pop at feminism, isn't it?
I think there is possibly also the aspect that the supervisors and lower level management that women at the bottom end of the pay scale work under are more likely to be uninformed about what they can and can't do within the workplace (or more likely to disregard certain things - such as the right to take emergency time off for dependants). I think they are probably also less likely to be challenged on this.
This is hardly the fault of feminism, it is the wider fault of society. I think it's poppycock to frame the discussion this way. Feminism has been fighting an uphill battle against entrenched interests, and a patriarchal paradigm. Advances have been made, ground has been won, but this sort of change was hardly going to be won in a generation, coupled with the fact any societal change is going to have unforeseen consequences.