I suppose that’s a fair observation, although I didn’t really consider the Prove It thread as a test of shooters as much of a test of rifles. Firing supported, after all. But it’s probably fair to say the voluntary participants in this forum, and further the subset of voluntary participants in that contest (if that’s what it was?) may not represent a valid representative distribution of “the average shooter”.
But...
There were plenty of 50 yard groups in that thread which demonstrated sufficiently small groups to satisfactorily define center for zeroing the rifle though, even by low cost rifles. The Savage I shot in the thread, for example, was only a $500 rifle, and there were a couple $450 CZ’s which shot exceptionally well. I think it was
@someguy2800 who shot even a scoped pistol which was clearly accurate enough to warrant a 50 yard zero.
I suppose, technically, my Charger pictured here is “zeroed” at 325 yards, since I dialed to hold on target. Walking my shots into the 8” plate, I could tell when most shots were on the plate, but some falling below the plate, then the next click, all shots were on the plate, as were the next click, but the 3rd click up meant shots started slipping off of the top. In other words, the pistol shoots about 7” at 325 yards with Remington Golden Bullet crap ammo, but I could still sufficiently zero to be within +/-1/2 click at that range. So I KNOW all of my personal 22LR rifles can easily be zeroed at 50 yards, and I also know with a large enough volume of fire, I can zero that Charger at 325 yards too.