Second, the pediatrician advice...
I didn't paste the whole paragraph. I have heard this said in other places too, but look at the state of the world of youths - do they have good characters and are they part of the valued community? Seems not to me. So, they are bad at school, and assholes :)
These act of teacher are acceptable and permitted by parents during that time. Which is I think has a positive effect.
People seem to undermine this kind of punishment, but it is actually part of the world. Jump poorly, you fall and hurt yourself. That pain is a lesson. I am not talking about beating children until they bruise.
The style of teaching has changed here I think, but not for the better. Teachers have no authority, and parents don't parent. So when do children learn that sometimes, they are going to have to listen and do what someone with more power than them says - like in the workplace.