^All those are totally valid points, but, like I said, it is the foundation of a very involved program that addresses those points by teaching children how to evaluate situations first, to recognize these pitfalls, and to support one another. It is also about teaching teachers to recognize these things, and ways of supporting each student -- including the ones, who, like you say, may not be very good at asking for help when they need it.
I have taught in classrooms where these methods were used from kindergarten on as well as in classes where they were not used at all. The differences are striking. This method has evolved into the Social-Emotional Learning approach, which you might be interested in reading about. It really is worthwhile, and the evidence thus far supports my own experience that it really helps prevent a lot of bullying.