Just for the sake of discussion, let's say that The United States of America is in fact the only nation on the face of the Earth and in the known universe where the open carrying of handguns is well-tolerated.
So what?
Are you suggesting that the abberation is a thing that should be relegated to regulation based on the prevalence and predelictions of what everybody else is doing?
There are a few things that make The United States of America different than any other nation on the face of the Earth and in the known universe. Generally those are the things that intice folks from everywehere else to want to come and live here. While the toleration of the open carrying of handguns might not be, in and of itself, one of those things that intice others to want to come and live here, it surely is indicative of the overall reasons.
So, again - So What?
stay safe.