Quite. Also, not every musician is involved in the conservatory system. Not everyone is involved in the "Competetive" hired gun world of cut throat sessions. Lots of drummers are in bands with there mates where the blend of musicians simply fit.Abusive behavior on either the student or teachers part is bad teaching/learning theory.
Abusive behavior on either a band leader or band members part is bad business theory.
Abusive behavior is usually justified with some idiotic rational...nothing justifies it.
In Britain, at least, most drummers have lessons, when they want or feel they need them, from a perfectly reasonable teacher. They spend more time playing and practicing for the love of it rather than trying to achieve some mythical idea of perfection being sold by the conservatory system. A perfection they seem to percieve can only be achieved by "suffering" for your art.