arma virumque cano (et alia)
The store owners were lucky that this robber is an idiot. Dog Gone, no one is saying that a gun is the only way to stop a robbery. A gun is, however, an effective tool for that purpose, if used correctly. If you'd admit that, we'd be willing to listen to other techniques that would complement armed self defense.
I agree with Greg, though from this video it looks like the crook made the choice that he would rather abort than shoot a man.