Lada, I agree that if she teaches well a student should stay with her. I am also choosing to believe that what you mean is, “It is a good thing for a kid to want to please the teacher” as opposed to “Fear is an excellent motivator.” Indeed that is true if we are training an attack dog, but this is not the case here.
I think that some teachers I have known would be quite shocked by your statement as written, including some of the best known in the harp world. Jocelyn Chang, Stephanie Curcio, Chis Caswell, Laurie Riley among others…very nice friendly teachers but no one would say that they produced lazy students with bad technique!
Biagio