@Agatha It doesn't work because the people most likely to follow already existing gun-free zones aren't the problem.
Smoking and drinking are pleasurable activities that (mostly since we still have people being arrested for DUI/DWI) can be controlled for the few hours that a person can't engage in those activities.
How do you control rage and crazy? Something has changed in the last 30+ years. There used to be gun clubs IN schools and people weren't going in and shooting them up like this.