It's too much trouble for most of these Folks. That simple.
A store near us has a dog. He's been around for night unto twenty years now. They had another one with him but he died over ten years ago.
I know of several places that have a store dog, if that is the proper term. It takes a right personality of dog and owner to maintain one of them. Most People have a dog, that thinks he is master or protector, of his family and turf. It's natural. Any other dogs and maybe people are seen as some level, of threat. You can't have him run free with other dogs and people there. Usually it's jsut other dogs being the problem. Our dog is typical. Well behaved and friendly but any new person coming into his home or on the property gets a greeting that will frighten some to death, except little kids.He thinks all little kids are his kids. Perhaps there is some school that will train our dogs to be sociable under all circumstances but everyone's dogs would have to be a graduate and neutered or spayed, for that to work. Until them leashes or keep in the coach, has to be the rule of the day.