gary b, great questions and I will give it a go. To me, the QB may get more scrutiny than other positions simply because they are usually considered the leader of a team or at least leader of an offense. 99.9% of the time everything starts with the QB and they touch the football more often than any other player. The success or failure of the QB has a disproportionate role in the success or failure of the team. Maybe that is why the terms elite and great are often used when referencing QBs. They are the most important players on the field.

Fair or unfair, I think Postseason/SB accomplishment does have a great effect on the status of QBs over other positions. Now if a QB has an "uneven" supporting cast, especially on offense, but somehow is still considered great/elite, that may be an exception to the rule. Dan Marino comes to mind, best QB (and considered great) to never win a SB, though he did play in one and got his team to the PS often. I don't know if winning a SB alone is a prerequisite for a QB to be labeled great/elite. I guess I would consider that as debatable when looking at a total body of work.

As far as position players, IMO, they can have an easier road to greatness, because they don't have to carry the same weight of a QB, who usually does get most the credit for a win, but usually get a larger portion of blame for a loss. Dick Butkus and Barry Sanders, both at the top of their positions, are two that come to mind.