I have had this position in my class more or less since I was a child. There are always one or two people or three or five people in the last row. These students are basically not very good at school, and then they don't learn how to chat or disturb other students in class, so the teacher puts them behind, and then a certain rule is formed by default in the class, that is, when the people behind chat, they chat quietly, trying not to affect others, because the students who have studied well are in front.
Whether the teacher's behavior is appropriate, if the students really didn't save the teacher's behavior, I think there is no problem. Some people may disagree with me and think that education should be aimed at everyone, but as long as you have been to school, you will know that there are always a few mouse droppings in the class. He doesn't study himself, and he won't let others learn other people's homework. He takes classes to consolidate others, let others chat with him, or let others send him notes.
Teachers certainly hope that every student can get better grades, because in any case, teachers manage this class for one year and spend almost the same time every day. If every student in the class can study hard, get a higher score and enter a better university in the future, it is certainly a happy thing for the teacher, but some students just don't study, which is not a problem that the teacher can solve without hard work. Parents are not well educated. Do you think teachers can educate well? The best choice is not to let these students affect other normal students.