It comes down to what I always say. Nothing happens in a vacuum. This behavior that men are seeing did not just spring up one day, apropos of nothing other than women getting a wild hair up their butts.
Just because men have been blind to it (by choice, because women have been speaking about this at least since I was a girl, so 3 generations now. 4 if you count generation Alphas, the oldest of whom are teenagers now, I think).
It really is what PUA, alpha ideology, redpill, and the culture of manhood has done to gender relations. The culture of manhood has changed significantly from prior to WWII. It's made men less desireable, IMHO.