The school's job is to teach reading, writing, arithmetic, history, science, geography, ect... The schools job is to enable those kids to function effectively in a free society, not to indoctrinate them to perform as sheep in an authoritarian one.
wintertime: To maintain an orderly school, speech, press, free association, and practice of religion **must** be restricted.
In other words, as wintertime says, for the school to do its job of teaching "reading, writing, arithmetic, history, science, geography, etc" a certain amount of discipline is necessary (I don't necessarily agree that most schools restrict practice of religion, however).
If one feels the public schools need to be destroyed, cheering the destruction of discipline within the schools probably makes sense.
Otherwise, it is contradictory to simultaneously decry discipline and the poor performance of the public schools. They will not perform well if there is no discipline.