@widewing The old guy in your video illustrates my point perfectly. He's sure brave, but he's also clearly target-locked and isn't clearing his background properly (or at all). His barrel control goes from OK to non-existant, he doesn't take a sight picture once, and he has no concept of EOF rules, so he keeps shooting as they flee. He's actually lucky he's a bad shot, if he'd managed to hit one in the back it would be murder. Not to mention if he killed a bystander with his inexecusably bad drills. Fortune favours fools, I guess.
The criminals in this video also demonstrate my point. They thought they knew what they were doing, had their weapons out and ready, but they panicked and ran when they got under lethal stress. This is also fortunate for old guy and everyone else there too - had they been a bit more switched on this would have become a firefight, and the criminals sure aren't going to be clearing their backgrounds. Basically this armed citizen hero escalated a situation where innocent people were going to lose some cash to a situation where innocent people were lucky they didn't wind up dead.
Brave? Sure. Smart? No.
I have no sympathy for the criminals here, but you have to think the big picture through. You can quote all the statistics you want, and I could show you a bunch of videos illustrating criminally negligent armed citizens who weren't so lucky as old-guy hero here. However the bottom line statistic is that the person most likely to die by any particular firearm is the person who owns it, followed closely by that person's family and friends.
Again, not my country, not my problem, and I don't know the answer. I do know the more guns=more safety position is delusional. No nation has more gun owners (or people in prison) than the USA, but every first-world nation is safer. So are such paragons of freedom and security as communist China, Lebanon and Uzbekistan. If you want understand the psychology/physiology that makes arming schoolteachers a bad idea, read LCol Grossman On Killing and On Combat. If you don't want to understand, that's cool too.