I think you might be putting the blame in the wrong place because the gun is capable of fine accuracy.
The simple answer is that it is too much gun for the guys you saw and probably is too much for the vast majority of people who bought them. But the reason the gun is selling in such large numbers is that lots of people want the biggest, baddest sob in the valley and this is it. Then they discover that it hurts to shoot it... but they still got the biggest... baddest...
The guys that bought the 4" are the same ones who bought the first one... just biiger and badder
It really does take a very experienced shooter to do well with that much recoil but it can be done.
S&W was thinking, "oh goody" all the way to the bank.
True Mike, but most of the loads I brought were the equivalent of hot .44 Magnums which, in that heavy gun, are pussycats. You did shoot some factory ammo (thanks for the brass) but a bunch of factory ammo- especially the heavy bullet stuff- is a test for anyone.
One of the appealing things about the new 460 is that you can also shoot .45 Colt or .454 Cassul. That option is not available for the 50.