I fully agree. But at my school there is just one possibility (besides JROTC) as to whom the teacher would be and that'd be yours truly. I would carry concealed in a Level IIIA retention holster. That's be my only hope and I'd have to have all GLASER or MagSafe loads. But otherwise, it'd be no problem.
Interesting, I used to teach, I did not have a permanent room (where I could conceal a quick open safe in a desk drawer) so I would have to carry too. But I also coached and so had to change to gym clothes for those periods. I suspect a locked gun in the coaches locker room might be the best compromise. (I would have to get there from a classroom, wasting time, but maybe moving in the right direction, who is to know?)
Kids in high school are very perceptive, they would spot a concealed carry making the headlines and bringing out every anti gun parent in the school. The process would vary in each institution. Maybe because of how I had to migrate with the students I would not be as good a candidate as say the administrator or counselor.
My thoughts are that any improvement would be an improvement. Even if many schools or whatever could not comply -- enough would that the society at large would have some recourse other than waiting til the perp runs out of ammo.
I still remember when a gang member came onto campus and was confronted by the unarmed security monitor. He was street wise and pulled off a his roper boots and using them as a club he beat the guy black and blue until the authorities pulled him off the guy. I had never seen boots used like this. But if the gang member had a firearm...