On Guns and Old Guys and such

So today was the first time, since I left OK and TX, that there was a guy in my local grocery with a pistol on his hip.
I was really trying to figure out my reaction, when I came across him telling one of the staff why he was wearing a gun in the store. It was worth a linger over realtive merits of bagged chips. And it seems, his purpose is to reassure young women like her, and the elderly and frail, that they don't have to be worried about those "gangbangers and such" who want to shoot people . Guys like him will deter violence.
Then I realized what I was feeling - anxiety, and incredulity, mixed with a little downright hillarity.
Excuse me, Mr. ,you aren't a cop! Maybe you shoot at the range with your buddies once in a while, but you are not a trained specialist in public safety, and are well over the age when yuor reaction time starts to run rapidly away as your birthdays accumulate.
I know, because I'm younger than you and am well aware of the fact that things don't work like they used to, that's why most cops retire before they get to "late middle age".
You are the most dangerous thing on the street to me. Those gangbangers, thugs and miscreants are out there to be sure, and some of them are pretty frightening. But you, Mr. Lone Ranger wannabe, are really scary. The fate of innocent bystanders lies in a calm, steady, trained mind and temperment, and I would bet you aren't it.
Do you know that your "taking out the bad guy" endangers everyone near you? Not only escalating a situation that might not need guns, but those inacurate shots go somewhere, and you have no idea who might be there because you are so sure of your own skill - not only in truely identifying a real bad guy, but taking him out. What about the people behind him? What if it's just somebody's honor student in a hoodie and gangsta pants dragging past his knees who happens to cross your path and looks hinky to you - shoot first?
That's why cops are taught a lot of de-escalation techniques, using words instead of weapons.
If we are lucky the worst thing that will happen is, if you do run across some really bad guy, your own gun is used on you, not some family who happened to cross the street at the wrong time.