In 1991 (year I was born), a kid brought a sawed-off shotgun to my high school and held up a class, discharging something like 10 shots into the wall. Nobody was injured and everyone made it out alright. This did not get weeks of nonstop national news coverage like contemporary school shooting incidents do. The kid brought a sawed-off shotgun, and handgun legislation was the thing of the time (which has now mysteriously switched to rifle legislation for no perceivably valid reason). Also, nobody died, so there weren't any dead kids to use as the emotional bedrock for any sort of political activism.
When I was in high school, a kid at either my high school or maybe it was the school across town, got a felony for leaving a paintball gun (from the weekend or whatever) in his car and parking it in the school parking lot.
What's changed in the past 30 years?
Why can't it just be a hobby, or hunting, or sport. I remember having fun shooting at a range. Around 8th grade I joined a local small bore club and shooting range and we shot .22 rifles. It was tons of fun. It wasn't in US, not sure if those things exist here for kids at that age. But anyway I can definitely see people doing it for that reason.