Because, for one thing, the private schools aren't richer. And for another, the best teachers in advanced and specialized subject are academic researchers who p

Because, for one thing, the private schools aren't richer. And for another, the best teachers in advanced and specialized subject are academic researchers who prefer proven institutions over newer, profit-oriented institutions. Running private schools is difficult, and I know of several cases where German private schools are causing all sorts of grief to paying students.