With all due respect, I don’t understand this call to action. Faculty position is basically a zero sum game. If more women end up as faculty, fewer men will. So, unless it costs more to train women than men, I doubt any “investment” would be saved (and that’s not the point of gender equality anyway).
Btw, this maternal wall idea is nothing new. I talked to my mother about gender inequality in hiring many years ago and she was quick to point this out (didn’t call it “maternal wall” though).