From my point of view, teachers are not to be blamed for any student who doesn't perform well in the class because most students don't listen in the class and whenever you ask if they understood they will always say yes just for you to leave so that they could play.

At least I have tried the teaching job once, and I knew how hard it is for teachers, so I wouldn't blame teachers at all; parents have responsibilities over their children's academy. The fault shouldn't be put on teachers alone at all.