What you're saying, especially the part about "slightly better organised and attract students that care enough about their education" is talking point rhethoric and not anything substantiated in fact. The schools get a fixed amount of money per student from the state. If you have students with high socio-economic status, you can get away with having fewer teachers per student, as well has having teachers that aren't properly educated. One of the more prominent for-profit charter schools is the "International English School" (IES). They aren't only "English" for marketing purposes (because being an "English" school means you can do more marketing about teaching with "higher discipline"), they are also "English" because that allows them to get away with recruiting more teachers from abroad. This is what for-profit charter schools are about. You can't "optimize" what's essentially a service institution. You can only cut to better your margins. Or cheat, which they do. Not only by having fewer authorized teachers, but also by straight up inveting better grades for students, which is something that helps with marketing (see a pattern here?).