The problem is also that people in general do not seem to trust giving teachers guns to defend themselves and the students. Tazers, they might authorize, but in many cases, if that tazer fails to hit, you cannot reload and you will be dead. I don't even know if you can really "reload" a tazer anyway.
The "sit in a room quietly and hide" tactic is literally a sitting deathtrap for innocent kids and teens.
And of course there's plenty of fancy politicians and political bandwagoners out there to distribute their "gun violence" philosophy that guns are evil and dangerous to people- when in reality its the people who are dangerous, not the weapon. That assault rifle didn't pull its own trigger*
*Experimental Japanese robot guns excepted