I suspect the thing is that, sure, there's a reasonable chance you're innocuous enough. But say, in an unrelated incident, a kid had gone missing, and beforeha

I suspect the thing is that, sure, there's a reasonable chance you're innocuous enough. But say, in an unrelated incident, a kid had gone missing, and beforehand there was a suspicious stranger with no attachment to any of the kids watching them from outside the grounds. It later turns out the person was watching them to identify a target to kidnap. Then say the school did nothing because "they're allowed", on the basis of everything described. But now a child is missing and the school didn't act on an obvious potential red flag. Would the parents find that acceptable? No. Would politicians and their voters find that acceptable? Probably not. Heads would roll. Ultimately the school is managing its risk level by taking action in that situation.