I suppose another concern, though I think this is already a thing, is that if criminals see that a lot of people are armed, that means they need to be armed too, and the level of violence, when it happens, has therefore escalated. I'm not sure that qualifies as a concern though, since it's common knowledge any American can be armed, and guns are so easy to acquire in the states that there is no reason for a criminal not to be armed anyway.
We have enhanced penalties for crimes committed with weapons, which I guess are supposed to discourage the use of weapons in the furtherance of crime. I couldn't say off-hand whether they are effective.
If I were actually living in the States, or planning on it, then yeah, I'd have a huge personal issue with it. People just aren't armed in Canada, especially not with handguns.
Even criminal elements are often armed with rifles, not pistols, because it's just not easy to get your hands on a handgun here.
Pretty much any rifle is going to cause more damage than most pistols. Rifles tend to have larger, heavier bullets, more powder pushing the bullet, and longer barrels allowing more acceleration of the bullet. The main appeal of handguns is that they can be concealed and are more convenient to carry. Of course, it's not terribly difficult to cut down a rifle or shotgun to a more concealable size. Knock down the barrel and hack off the stock, and you basically have a rifle-caliber handgun or a shotgun pistol.
Where I grew up, if you are armed in public and you aren't a cop, it means you are in the process of, or about to start, shooting at people, so an armed civilian is to me an implicit threat: Cross me and die.
Because it's not generally legal for people to show you that they are armed, the only people you can see are armed are the people who are already operating beyond the legal bounds.
It's almost as though only criminals carry guns when carrying a gun is criminalized.
For an analogy, imagine if the law was instead about the right to bring your dog(s) to work with you. Now, I would be totally fine with that. I was raised around dogs, and I had friends who also had dogs that would have attacked if you threatened their family. Anyway, I'd be fine with that, but I imagine people who didn't grow up with dogs, and don't know how to interact with them without being bitten, they would be really nervous.
A few important disctinctions, I think:
Dogs have minds of their own, whereas guns are under the control of those who possess them. I can't make sure that my dog isn't going to bite someone, even though I think it's unlikely; I can be sure that my gun isn't going to pull itself out of my holster and start shooting people.
You touched on that when you mentioned that some people "don't know how to interact with [dogs] without being bitten." If someone else is carrying a gun, there's no special way to act around it to not get shot. Unless you want to count not attacking the person carrying it, I guess.
As dogs do have minds of their own, they require attention. If my dog comes to work with me, he's going to want me to play with him, he will need food and water, he will need to go outside and do his business. If my gun goes to work with me, it sits on my belt and nobody knows or cares; it doesn't interfere with my work in any way.
Ew, leather. I would never use one after seeing this picture: (although yours does look like much higher quality).
I don't know about higher quality, Galco has a pretty good reputation and lots of happy customers. A better design, certainly. That holster leaves the front end of the gun completely uncovered, which provides an opportunity for the front sight to catch on the holster while drawing.
It also doesn't cover as far back on the gun as I think it should. I get that the pistol maybe isn't fully inserted there, but look at these photos that come up when searching for that holster model:
The trigger guard isn't completely covered on either gun, and the trigger is almost completely exposed on the second. It doesn't look like the holster is formed to the gun in any of the pictures, so I'm having some trouble imagining there's much friction retention. Even if the leather wasn't initially soft enough to fold like your picture shows, it's probably not a great choice.
That said, equipment does wear out and should be checked periodically.
I do have a left-handed (in the waistband) kydex holster for the smaller gun that I use when I carry it on my left side, and I don't really have any complaints about it or the leather one shown earlier.