I don't know why it wasn't done away with 300 years ago.
"The usual lazy and short way by chastisement and the rod, which is the only instrument of government that tutors generally know, or ever think of, is the most unfit of any to be us’d in education... Such a sort of slavish discipline makes a slavish temper. The child submits, and dissembles obedience, whilst the fear of the rod hangs over him; but when that is remov’d, and by being out of sight, he can promise himself impunity, he gives the greater scope to his natural inclination; which by this way is not at all alter’d, but, on the contrary, heighten’d and increas’d in him; and after such restraint, breaks out usually with the more violence; or,
If severity carry’d to the highest pitch does prevail, and works a cure upon the present unruly distemper, it often brings in the room of it a worse and more dangerous disease, by breaking the mind; and then, in the place of a disorderly young fellow, you have a low spirited moap’d creature, who, however with his unnatural sobriety he may please silly people, who commend tame unactive children, because they make no noise, nor give them any trouble; yet at last, will probably prove as uncomfortable a thing to his friends, as he will be all his life an useless thing to himself and others."
-- John Locke; from 'Some Thoughts Concerning Education' (1693)
Unfortunately, in some US states it is still as if the enlightenment never happened.