You're missing the step where Teachers College of Columbia University first hijacked the teaching profession for a specific progressive philosophy that aspired

You're missing the step where Teachers College of Columbia University first hijacked the teaching profession for a specific progressive philosophy that aspired to a scientific approach to education, but went with pseudoscience around things like "learning to learn" instead. This provided fertile ground for fad after fad that later swept teaching. This created grounds to want to restrict teacher autonomy in the first place. I recently re-read To Kill a Mockingbird and was surprised to find a first hand account of what an initial encounter with this philosophy was like back in the 1930s.