If teachers conceal carry the students would no idea that the teachers were armed or not.
And I'm not sure there would be any harm if the students did know that their teachers were armed. If I was a student today I would want my teacher to have a firearm ready to protect me. JMO.
Teachers lose it, just like everyone else. Surely you read of crimes against pupils by teachers? Or teachers themselves committing acts of workplace violence?
Since guns aren't allowed on the campus where I teach, most of this acting out has been pummeling or punching or, in one case, an attempt to strangle (one faculty against another; one of them lost his job - but it took a year).
If every teacher had a concealed carry permit, we'd see more people getting shot by teachers' guns (and yes, the kids would know they were there, some teachers would brag about it and the kids would start looking for signs).
Where would someone like me actually wear this gun? Do I carry a tote bag all the time? (Because I don't carry one right now). Would it have a special closure? How helpful would that be if I needed the gun right away? Would I wear a bulky coat so that I could have a cross body holster? It would be instantly obviously why I had changed my normal way of dressing.
The hot-tempered teachers I know are already a problem. I would stop going to faculty meetings if I knew any of the hot-tempered ones were there. Right now, the worst they can do is throw things and get in people's faces.
I also think that given that bullets travel through persons and into other persons, that unless teachers all did military style training a couple of times of year and committed to one day a week at the gun range, we'd have a lot of innocent people dead.
And yes, a lot of teachers would just quit. It's a profession with a lot of gun-phobic people.