Why are professionals so afraid of amateurs? Isn't it obvious that people play sports because they enjoy doing so? The ones who can produce reliably under pressure become pro's. Once money enters into the picture it becomes irrelevant whether or not they still enjoy playing.
When kids get interested in sports or in music the degree of their obsession usually becomes clear early on. A kid who is obsessed with the piano will play nonstop, as I did, starting at 6:30 A.M. every day. (Note I said "play" rather than "practice.") Why shouldn't kids who are not so inclined be taught to love their playing because they love music? Isn't loving music the whole entire point? More simply put, why can't we get used to the idea that cultivating mature musicality (on a non-professional track) requires a special kind of training: that in which the ear that demands satisfaction is not the teacher's or the parent's, but the child's?
Isn't that preferable to producing generations of quitters who hate themselves for quitting, and who wouldn't dream of inflicting piano lessons on their own children?