A bit surprised that Bob Milek hasn't been raised in conversation yet?
I think the real answer is 2 fold, because there is 1 group of people already in elk country so can change rifles and loads to grow their experience and a 2nd group that has to travel to elk country more infrequently at at additional cost, so tend to plan more for contingencies, usually selecting heavier choices.
This scenario tends to blur the facts as the other group see it. Both can be right and have adequate loads but being able to place the shot can be the game changer regardless of the load used.
