Why are there so many threats to schools?

Angry, hurt kids have always existed and they often turn into highly toxic adults if they make it that far. Their internal rage needs an outlet and that is most often in the form of violence, either to the self or to others. School shootings became a popular outlet after Columbine, largely because of the huge media attention that it got. It's the same as how ISIS inspired terrorist acts were happening frequently in the west for a good while. Same angry, hurt people latching on to a trending outlet under the guise of believing in an ideology. We can ban weapons, it would have an effect of some kind, but the real trick is to enable effective early intervention for these damaged kids rather than shunning them, leaving them in broken homes or putting them into a broken care system where abuse is perpetuated. Nobody healthy and happy wants to kill people.