Most teachers I know (I teach teachers at a university) rely on pedagogy, methodologies, strategies, and are primarily ignorant of subject matter. If their PowerPoint cannot be used, they cannot teach.
When students are unruly, they have no concept of the psychology of discipline or learning. Few teachers even bother to learn educational psychology: at most they study a little of Pavlov, Piaget, and worse of all Marshall McLuhen. If they do study the history of education, it is usually focused on the late nineteenth century to the present, rather than going to its ancient roots: discovering the mistakes and successes of the past so as to use or avoid similarities in instruction.
Today's teachers are basically unfit. Their inadequacies frustrate, bore, or build resentment against the teacher and education.
It is past-time that we return to a classical liberal arts education that asks the primary interrogatives, and that teachers are not certified until they prove themselves to be subject-matter experts. All the games and whistles used in classrooms today are worthless if they do not expand the knowledge of the student.
Even worse than the games and whistles are the textbooks of today: They are opiats at best.
I failed an entire graduating class of would-be English teachers who could not explain why (in most cases) adjectives come before nouns. All of my students in the Psychology of Learning failed because of their own lack of responsibility. Few set aside time for reading, research, investigation, and the full plethora of the conduct of inquiry. It is for reason, as can easily be googled, that over 7000 high school students drop out of school every day. Learning is seen as a waste of time. Students are more interested in specialization, even though specialties last at most 5 years and they are at a loss of what to do when unemployed, and cannot adapt to a situation, adopt further skills because they have too narrow an educational background.
When I teach a course, I incorporate environmental and ecological studies, history, law, the arts and sciences, as teaching any foreign language is more than just memorizing words. Phrases are important but those that are considered proper (academically correct) are of greater value than any vulgar (street language) idiomatic expression. Unfortunately, today's teachers are those who are busy showing pictures, using tapes and slides, and have not a clue as to what is essential.