That's an excellent point. Although looking back on the teachers I had, I'm not sure they were all that much better back then. I encountered quite a few legit mentally ill teachers. We tried to get one of them fired when I was in 5th grade. We called it "Operation Webster Fire". A few of my best friends had her as their teacher, and she ran the after school talented and gifted program that I was in so we all witnessed her batshit crazy behavior. She'd lock herself in one of the supply closets in her class room and chain smoke while babbling nonsense to herself or some imaginary entity. Along with being unhinged, she was also physically abusive and a delusional, compulsive liar.
I mounted a tape recorder under her desk, after school. Some other kids brought them in as well. One kid had a video camera he brought in from home. She found one of the recording devices and immediately went on the offensive. This wasn't the first, second, or third time she was being accused of being unfit to be a teacher. I never got in trouble, but several of her students got in school and after school suspension. I'm I'm all for spanking, but she'd hurt kids and then lie about it. She ended up getting fired about 10 years later for breaking a kid's arm.