I didn't say that. But the skills needed for a gun toting teacher to ward off an attack, or take down the attacker, in a crowded space full of innocent, panicked bystanders are advanced skills even for a police officer, that require significant training to learn and continuous training to maintain. Or do you think we should just hand a Glock and a shoulder strap to the Geometry teacher, and wish him or her luck? It's also my opinion that doing so safely and effectively requires a unique personality (calm under fire, willing to move toward danger, and kill a child when necessary), more suited to those who choose to be cops than those who choose to work around and educate children.
And I've been around guns enough to know that 'concealed' isn't really concealed if you're spending hours with an individual. Kids will know week 1, if not first period day 1, they have an armed teacher.
Just seems simplistic to me - "Gun violence a problem? MORE GUNS is the answer!" - and the suggestions nearly always fail to even acknowledge the obvious and substantial downsides, much less weigh them against the expected benefits.