I don't know about you, but I know more than a few teachers socially, and I can tell you with an absolute certainty that most, if not all, of them clutch at their pearls like Margaret Dumont at the very idea of a gun inside a school. I can also tell you with absolute certainty that most, if not all, of them wouldn't know a carbine from a carburetor. So, even though I haven't heard an opinion from all of them, I can safely assume that they responded to Wayne LaPierre's called for armed guards in all schools with ignorance expressed as outrage or mockery.
To many of them, putting an armed guard or allowing staff to concealed-carry inside a school would be like releasing a basket full of cobras. Their fertile imaginations immediately conjure up images of a teacher or a guard having a bad day, "snapping", and then opening fire, or an emotional teenager losing it, grabbing a weapon from an adult, and shooting up a classroom or two. They find comfort in thinking that because there is a zero-tolerance policy in place and a sign up which declares the school a "Gun Free Zone" that they are protected.
So far, the only major thing I've seen a zero-tolerance policy and "Gun Free Zone" in a school accomplish — a rural school in a county where most residents hunt and many out-of-towners come to fill their deer tags every year — was to nearly get a teacher fired for forgetting that his hunting rifle was in his truck when he drove to work. Imagine that: being fired from your teaching position for having a weapon on school grounds. He probably would have had a hard time finding a decent paying job in another line of work, much less worked as a teacher ever again.
But this kind of irrational fear is limited. Just as the fear was induced through indoctrination, so could it be overcome through training and rational discussion.
The real trouble is with the teachers' unions. Don't kid yourself that their concern is for the safety of their members or students. No, their concern is whether they will get their pound of flesh or not. How will contracts deal with guns? Will teachers get some sort of "hazard pay" for either working around guns or carrying one themselves? In their world, giving teachers and staff the freedom to take control of their safety and concealed-carry is an extra burden. After all, teachers are already babysitting your little brats all day long and now you want them to be overtly responsible their lives, too. Ridiculous!
Of course, teachers are already overtly responsible for their students' safety (and, by extension, lives), but many teachers and their unions prefer to pretend that that isn't true. What many of them would prefer is to continue living in a world where magical thinking, embodied by the Zero-Tolerance Incantation and the Gun Free Zone Sign Talisman, keeps madmen from targeting schools. As long as they continue to put their faith in these things and absolutely refuse to imagine that real, proactive measures which includes the possibility of one or more armed employees, all of their gun and mental health policies add up to nothing more than over-priced crossed fingers.
If they care as much about The Chill Drun as they say they do, they must do better than that.