Ya’ know, it may have a bit to do with who is doing the buying of Rugers versus Kimbers. Most guys buying Rugers aren’t going to be afraid of turning a screwdriver and running a bastard file, while I expect most Kimber buyers will be looking for a more turn-key product, not interested in popping the hood. Kind of the same difference between a guy who buys a Camaro and a guy who buys a Corvette.
Luckily for both, the fix is pretty simple.