There are occurrences of school shootings in the USA, with people getting very upset about every such incident. But it's very easy to bring a gun into a school: no metal detectors, no guards, no baggage scanning, etc.
Meanwhile you cannot even bring too much water into your carry-on luggage on board of an airplane, not even a baton, not a knife, just no weapons possible. And you may be stripped naked by TSA to ensure that, but also so that they can confiscate any drugs you may have.
Shouldn't compulsory public schools be at least as safe as airplanes are? Sure you cannot bring down a big building with a public school, but you can harm multiple kids and that's a loss. Isn't it neglectful that we're not scanned when we enter public buildings different than airports?