I went to American public schools my whole life and never saw any evidence of bullying.
An interesting perspective which I feel might be the actual core of the problem. I grew up after the Revolution, so I can't make a before/after comparison, but (as I mentioned in a different comment) I see a tight connection between how aggressive other students were and how bad their family situation was.
> Math for math's sake was never my thing. I only started to really like math in university when I saw its potential to solve real world problems.
Perfectly legitimate. Pushing hard math early on can actually put you off the subject forever. Some of us started liking it in university, but a lot of capable students decide it's just not for them. With a different approach many might have ended up understanding and maybe even loving it.
This has changed for the worse with capitalism and social inequality. We had some bullying back when I was a primary school student but it was physical bullying by higher graders towards younger students and it was mostly done outside the school. We had none of the psychological bullying that you see in the US and to a greater extent in Korea or Japan. We had roma and very poor students in our class. There was also almost no bullying during high school. The more odd kids were usually ignored and had friends of their own.
> I think that those hard problems were actually very rewarding
Well, maybe rewarding for some. I didn't like them and would rather go outside and play or ride my bike in the neighbourhood. Math for math's sake was never my thing. I only started to really like math in university when I saw its potential to solve real world problems.