Exactly. It took a little time for these female athletes to realize what they were up against (that it wasn't just a one-off here and there, but a trend), what the consequences were, and to decide to organize with their competitors to fight this.

These young women aren't political activists, but athletes. This behavior probably doesn't come naturally for many of them, especially when they've been harangued for years that only evil bigots would ever hurt the feelings of a transgendered person. This is especially the case in a college environment, where the administration might be threatening to drop them from the team, pull their scholarships, or kick them out of the school if they don't play along.