I can see how people might have grown up on your planet, and perhaps didn't entirely need a rifle that would shoot better than 4 moa, or expect one. When everything around you is also a 4 moa rifle, then you might not even really know that you could have something better. When zeroing consists of pegging away at a rock or beercan at close range and calling it good if a shot hits, then no doubt a 4 moa rifle's as good as any better one. And if your hunting terrain and techniques match, such as potting deer wandering past or beneath your stand, then it would make no difference to your success.
FWIW there were some aspects of that world in my youth. For example, surplus rifles were cheap and often used for pigshooting. They suited this well, as pigs were available by the truckload, often in thick stuff, and a rifle might need to withstand being dropped in mud and knocked around.
No one considered 4 moa especially accurate though, and the cheap pig rifle was a bit of a special case, with many more accurate rifles being sold here. You'd see the ads for $35 Carcanos and SMLES, but the gunshops would have racks and racks of scoped bolt-actions too: Remingtons, Rugers, Winchesters, Brnos, BSAs, and also a fair number of fancier ones. I remember a time when there were about half a dozen gunshops along George St in Sydney, back in the 70s, and you could have a nice day out walking from one to another and admiring them. If you had the money you'd say "yeah, I'll have that one", and walk out with it. People wanting to hunt deer, or to reach out across teh paddock and headshoot roos, or goats, wanted something a good deal better than 4 moa. Even back then, as I recall, 1 moa was the yardstick for an accurate rifle
FWIW in the late 70s I was using a .22 for rabbits and foxes and the like which would shoot 5 rounds into 1/2" at 50 yards - good enough for me to win the odd prize in field rifle competition. I had a couple of surplus rifles, including a 7 mm Mauser 1895 and a .30/06 Colombian, and then got a job with a gunsmith where I built a sporterised No 4 .303. All of these would easily beat 4 moa by a large margin, the No 4 shooting into about 1 1/2" at 100 yards ( once shot a 5" group at 500 yards with it, but that was a bit of a fluke). I then bought a Rem 700 BDL with a Weaver K6, which put the first two 5 round groups (factory ammo, which came with the rifle) into an inch each at 100, and proceeded to reach out to various game from rabbits to deer with it. .
There was never any of the "shoot at a rock and call it good" either. My family were pretty keen, and so we'd do plenty of practice. We had an informal range on the farm, and as well as that I, like my father, would go to the rifle clubs. My mother's side of the family also liked shooting. They were Swiss, and used to practice with an air pistol in the hallway, and because of them I joined a Swiss rifle club locally, and used to go to the annual Schuetzenfest. I used to do quite a lot of competition, both with them, fullbore (long range), field rifle (hunting rifles), and with cadets. As well as hunting rifles, I had match rifles too, which would shoot a good deal better than 1 moa - I had rifles which would shoot moa-sized groups from prone with a tight sling, unsupported. We'd always check zero - on paper - before hunting too.
This was the world I grew up in. Like "4 moa world" I have no doubt that it wasn't universal, even here.
