I'm the same way. At the last school I did, I was griping about my mistakes before the instructor could say anything. So he ended up being quiet the whole time, or saying "yup". So me not wanting to do schools isn't me saying that I'm ready for Formula 1. Just that, like you said, I know all the theory, I know what I should do, now it's a question of enough reps until my body learns what my mind knows.
So saying that everyone can learn from a school is a silly blanket statement, and suggesting anything else is a poor investment is pretty rude. The same is true for the instructors - I'm sure if one instructor went for a ride with another, he'd have some suggestions for him, or for Michael Schumacher.