I love these pseudo intelectual arguments that try to explain human behavior. It's a fact that there are biological differences between men and women, that is obvious. But people love to pull sophisticated pseudo scientific arguments that rest in very weak premises, which often ignore the many other factors (for example social and political) that also influence the outcome this argument is trying to explain.

So, this women are bad at spatial awareness so they are bad at math. How do we objectively validate the premise in the first place, without taking into account biases that can influence that very premise, like social, nutritional and political factors? Are math skills only influenced by spatial awareness or are there other factors that influence math skills?

So this argument is actually a subjective prejudice but worded in a way that seems to be scientifically valid. One consequence of the enlightenment is that we started to try all the time to disguise a subjective prejudice with an objective truth. After that we had eugenics, (pseudo-) scientific race theory and all kinds bad justifications, but the truth is that people want to exploit other people, and they think that coming up with moral and scientific explanations for this exploitation makes them sleep better after making numerous atrocities during the day.