But very easy to be a bad teacher.
Just watch this clip from Waiting for Superman.
Take note of how few teachers get fired.
And the vast improvements even a small dismissal in poor performers would have.
This is why the US education system is a Red Queen's race.
Scary how it's considered wise and progressive to force the Medical Industry to act like the Education Industry.
All from Ace of Spaces which shows some truly sadistic bullying done by a teacher on a student. Who of course wasn't fired.