Yeah, I can see how hierarchical organisations benefit certain goals and activities. I was speaking specifically about the goal of teaching rationality, in case that wasn't clear from context. You don't need a central authority to control what is being taught so much unless you are teaching irrationality (c.f. Scientology, Roman Catholicism or any political organisation).

You could probably run a million rationality courses a year using just a wiki and a smartphone app. (Left as an exercise for the reader)