High school bans backpacks to make school safer

Not sure why they're banning bookbags when they can just add metal detectors. There only been 1 case of someone bringing a bb gun to my school and that was before they added metal detectors. After they added metal detectors we have not had anything happen to our school. People also, don't sell drugs in my school because of it and it's pretty much safe as long as you're monitoring people going in and out. Also, my school had exit doors that would ring very loud and security would be there in under 3 minutes. So, seeing that people want to ban bookbag to keep kids safe is one of the dumbest shit I heard since people can have an ar on themselves without making it look obvious.