Why do some teachers punish all the students in the classroom just because of one or few students?

I’m not saying all teachers do that but there are some who do this.Like for say if one student or just a few did something wrong, aren’t discipline, recent troublemakers,were lying about something and didn’t want to tell the truth,or anything the teacher found bad to her she would punish all the students(and I don’t mean a physical treament way) by saying they’re going to get homework for the whole holiday or extra homework,won’t let none of them play outside for recess, cancel special activities, etc of whatever she(most usually a she) or he decides to put a frown on the students faces. I remember a lot of this kind of stuff used to happen when I was in elementary school and always asked myself, “why make the other kids suffer for someone else ignorance or wrongdoing”? “Only punish that individual. Not anything serious, thought it was just stupid.

Has this ever happened to you in school or when you use to attend school? What’s your opinion about it?