No one is criticizing the teachers; its the training that needs to go. Giving the teachers a one-day course in attacking a gunman in pairs and from behind in unrealistic training scenarios is just as bad as banning magazines and guns - both are attempts to do something even when you know the something is just setting people up for failure.
Hope nobody misunderstands me . . . I think that fighting back with improvised weapons is a realistic response if we can't arm and train a few in every school. But, in my left-leaning state I don't see armed teachers any time soon. I advocated for it after VT, and was shot down (pun intentional!).