They do not learn how to manage time for themselves. One teacher refused to open the windows or shades and kept the class in a continuous semi-darkness. The psychological impact of sitting in a dark room every day is devastating. To not be able to look out a window can certainly be likened to a prison sentence. Legally drugging kids with amphetamines or other psychotropic medications in order to control behavior.
Kids learn that they have no rights with respect to their physical and intellectual well-being.
I would cringe every time a particular teacher walked down the hall with her class. She always had something mean and nasty to say to some poor child. Kids learn that disrespect, cruelty, and physical force are the means used to getting what they want. They learn to treat themselves in the same fashion and they equate learning with drudgery, confinement, and pain. Kids are conditioned to have a short attention span.