These 6 men revolutionized teaching. Every teacher should be aware of their works and how they apply to the classroom. Especially considering the fact that between the 6 of them, their theories are central to modern teaching.
Truth. Yes, some teachers may cause minor problems in specific classrooms, but the large majority is trying to improve the system one step at a time, even though most large decisions are up to administration, the school board, and local and federal government, which we can't do much about.