Outside of Japan maybe, but it's something that would work in that culture. From my last trip to Japan a couple of years ago, I saw vending machines everywhere. In urban areas, there would be one every couple of city blocks in urban areas; I even encountered a few in the middle of park trails in relatively more secluded areas (e.g. more or less the middle of a forest). All these vending machines appeared unattended, but they always had inventory.

It always comes down to that, but what's stopping a company from hiring someone located anywhere in the world with a big monitor to stare at 20 feeds and just hit an alarm and call the cops when people get disgraceful? Have the cams only flip on with motion even. Could probably do it for dollars a day in some countries.