Ideally, each pupil shall be taught according to her or his individual preferences and talent, and according to the available groups (bands, orchestras). If compromises are required, the best ones still depend on the pupils. Unfortunately, the weakest point is often the teacher, followed by the parents; they may well choose the way of least resistance. Most of today's teachers (in Europe and North America), unless specialized for music, do not play any instrument, as a result of the previous generation of teachers who were dealt with as suggested in the OP. In other words: once more, a dated satire has been outrun by reality.