So really, you want armed teachers, but you don't want to have to pay for them. Yo uwant them, out of the goodness of their hearts, to just take on that responsibility and cost to educate and arm themselves.
Tell me, where are these teachers supposed to get the money to buy the guns and ammunition and pay for these CGC classes? Where are they to get the money if their insurance decides to up their rates because they now own and carry firearms (I should note I'm not sure this would happen, but given all the other crap they increase rates over, it seems logical)? What about the school itself, do they pay those teachers more? What happens to their insurance rates if they now have armed teachers on campus? Where are the teachers to store their weapons, are they to carry them all day, everyday?
Oh thats right, you don't really care about all that complicated crap. Much easier to just say 'Fuck it, let teachers arm themselves and let god sort it out'.