Wouldn't that have been a much better solution, and a simultaneous proof that we all need to have guns at all times.

Hasn't America tried this option, every citizen in Dodge City wearing a gun belt. Maybe if we compare the past 200 hundred years of a gun toting USA and a gun free (largely) Europe it may give a clue as to the road to follow. That said, it is a complex question but as long as selling weapons is a big business and a political lobby there will be problems. Why is there no research into non-lethal weapons. We spend zillions on finding more effective ways to kill and peanuts on finding ways not to kill. Maybe we just enjoy killing.