Basically. It’s up to you in that moment whether to interpret “guys with guns going into a school” as a threat or an infraction. Perhaps they’re just plainclothes cops on their way to teach DARE? How would you feel you called the cops and they came and gunned down the principal for leaving work early for his hunting trip?
Back before mass hysteria, I mean mass media, students and teachers alike would often bring guns to school because they came straight from hunting in the morning, or were heading out that way again after class.
There’s nothing by itself that says “man with gun + school = tragedy”. That’s an unfortunate trend we’ve seen play out on the news too often, but it’s a fallacy to assume that, because it happens a few times a year across the country, that means it’s a virtual certainty that any time a gun is brought near a school, dead kids will result.
On the other hand, the vast majority of the country shares your apprehension about guns and schools now, so chances are that suspicious looking armed gentlemen on school property are up to no good. But that’s a probability game. Simply possessing a firearm on school property is still not a threat. But maybe the odds that it will become a threat in the near future are too much for you to ignore. I don’t personally know what those odds are but I bet they’re far lower than you think.
What about other gun free zones? Sports stadiums and colleges and the like? Why can’t college kids have guns? They’re free adults, it’s their money. Why not allow guns at airports and courthouses? There’s always a greater threat in large crowds, but I’m not sure why the specific crowds at airports and football stadiums are in more danger than the crowds downtown or in the park (or in line for security).
Society depends on us all trusting each other to a certain extent. I could walk down the hall now and strangle one of my weaker coworkers, or beat him to death with a chair, or something. But I won’t. I could also walk down the hall and gun him down in cold blood, but I won’t. We trust each other not to do these things as a matter of course. Turns out there are some signals that lower that trust irrationally, like hoodies, or tattoos, or speaking a foreign language, or guns. Not sure how to handle that fact, but I think allowing those prejudices to drive policy is a bad idea.