Teachers putting students against eachother TwT

Hihi!! Talking from personal experience, but why the heck do teachers in my school keep putting me and my classmates against eachother?? For context! I live in a small city that's confined by an ever tinier city, so most of the teens from the other city come to our schools due to their city not having any. And tell me why, our teacher literally calls us by the names of where we are from?? A thing happened, and the teacher said that somebody from our city said that the guys from the other city were trying to remove her from our class. Which is not true! We were ALL voting to get her out of the class, and now the guys from the other city think there is a snitch that hates them . I had to justify myself with one of the girls which is insane. What is going on these days T-T