It's illegal to pay men and women differently. Just because a woman doesn't open her mouth and go after a raise isn't our problem. And don't blame society for "raising" girls that way. People should start taking personal responsibility for shit.

So argue against affirmative action as well. . Scholarships as well as everything in life should be based on merit, not ethnicity, skin color or gender, correct?

Pay gap is real or not depending on how you define it. In a given year, on average a woman will earn less than a man, because of a multitude of factors: they work shorter hours, on less paying jobs, with more holidays, they're less likely to negociate a salary when being hired, less likely to be successful during aforesaid negotiation, less likely to ask for a raise, more likely to be seen as unusually aggressive when asking a raise like a man does, don't think of high salary as an as important thing as men do.
Some of these factors can only be dealt with through self-improvement. Some of these directly come from social biases.

Pay gap is a complex issue, and saying "It's patriarchy's fault, fuck men!" or "Move your ass, woman!" is way too simplistic a solution.