To reach that "pay gap" statistic, you have to intentionally use unmatched samples, disregard best practices for controlling confounders and perform no covariance analyses. In other words, you have to commission and then willfully parrot the conclusions of someone without even a basic grounding in undergraduate level stats.
That's how you know it's all ideologically motivated. Policy is not dictated by an average A-level student's coursework unless you like the conclusions enough to ignore their validity.
FWIW, as you probably know, as soon as you introduce matched groups, any alleged difference in pay by gender disappears completely. It doesn't even just disappear in the strict scientific sense of "no longer statistically significant"; it literally ceases to exist (with, if anything at all, a slight bias in favour of women).
(Sorry for continuing the off-topic tangent but this stuff bothers me too and who really wants to think about the game anyway? It basically ended as more of a political flashpoint than a sports contest.)