I think he's right. Actual shootings are certainly extremely rare, but that doesn't mean that the main goal of the schools can't be to stop them. School systems tend to be highly irrational like that.

My high school was fairly strict on rules and regulations, and my time and movement was managed and regimented to an extent that I've never experienced before or sense. Much of this was due to misguided safety rules. That was before Columbine, and from what I hear things have become far worse now.

Such might be reasonable if shootings were a serious threat, but the aren't, as you point out, so it's basically just wasted.