My sixth grade teacher decided that I would be sent outside of all her classes (all of them except music and PE) if I missed any homework I had failed to do fro

My sixth grade teacher decided that I would be sent outside of all her classes (all of them except music and PE) if I missed any homework I had failed to do from the start of the course. She didn’t even notified the principal, which asked for an explanation when he found me wandering on the soccer field the 5th day this occurred and then notified my parents. After a series of homework related problems where even the principal had to intervene on my behalf, I was able to pass grade, only for the same teacher who had been teaching the same grade for more than 10 years to pursue a change of grade. Afterwards, since the principal on which was in charge of the following grade was more sympathetic to her case, I was spelled of said school because I missed 5 homeworks in 2 months. Afterwards I heard the teacher came back to her old position. To this date, I still don’t understand what the hell was going on on her mind, yeah, I was irresponsible, I was defiant, as there was some formalisms which I found absurd. But I was a quiet child, who payed attention to class and wanted to be left on his own and was able to ace any test because I did like learning. I didn’t even had friends so it’s not like I interrupted her class with any chatter. I guess the lesson is that some people are petty?