I taught Spanish in high school for 20 years. The teacher's job is to complete objectives for the subject matter being taught.

When a child misbehaves, that is taking instructional time away from the other students. The other children that are behaving are being cheated out of instructional time because the teacher has to deal with the child that is misbehaving.

If the children get guidance at home and they are exposed to positive role-models (parents), then they will most likely behave in the classroom.

This will hopefully lead to children becoming upstanding
citizens.