Midnight Honesty at Noon: I have met the Enemy:
For my money the biggest reason specifically actors aren’t stepping up (outside of the fringe) to positions of leadership on the organizational side is that we’ve trained them to do as they’re told.
In American theater most people come to the business via education. They discover it in high school or college and are trained in either pre-professional or conservatory programs. That training is largely carried out by lapsed or current professionals who teach their student to operate in the system and the hierarchy they know.
That system is of course the current system, and that hierarchy is the primacy of the text, then the director, with the actor doing as they are told.
And they are listening.