Many teachers are on a power trip.
Rather than engaging students in discussions of different opinions, they often try to present their opinions as the only correct interpretation. Although it is nice to consider a teacher's point of view, I found it offensive to suck up like many of them demanded. I also, found many teachers simply weren't teaching me anything. When I really wanted to get work done, I would stay home from school where I could really learn without being pestered by teachers. Other kids did not have such patience or foresight, and erupted with what is labeled as Attention Deficit Disorder.