I mean...have you ever heard a teacher strictly saying "I am not your friend" to their class? Well I have and I don't mean to exaggerate assuming what that teacher said is only figurative, but don't you think it will send a negative message to their students? Follow me on this picture:
-literally though-
And if the teacher is downright strict..I doubt the students would have a good time sitting in the teacher's class. Well, I know a few teachers in my school who acquires a good reputation with their students, they did so by being a friendly sport with their class, thus they are treated much properly than the teachers who are otherwised. Anyone familiar with this theory: "In order for an educator to derive an attentive class..he/she must basically set up a good relationship with his/her students" Its true in so many ways. Well I'm not saying that teachers should'nt be strict with their students...no. It is inevitable of their strictness to part-in when they are teaching..but it is no harm to keep a good-sporting relationship between teachers and students. Come to think about it..whats the point of a teacher being furiously strict all the time? It would only spark hatred in the students' eyes.
P/s: If you are always referring to Wikipedia for your source of information..you might wanna click here. You'd be surprised to know just how many blunders Wikipedia obtain. =P