Teachers Unions & The Department of Education
Back in my day, High School kids were at a far higher level of maturity. Many of us enlisted at 17 & 18 during the Vietnam War (conflict!). We were able to have gun clubs because the teachers who taught us were not pushing any agenda other than education and maturity.
There were gun clubs (in fact it was common to see pickups in the parking lot with a window gun rack and a shotgun) and yet no school shootings. What changed? Teachers. I had many teachers who fought in WWII, none push a Liberal agenda on me, and none asked me to question my sexual identity.
