I don't think winning a championship should define a player in a team sport all that much, except maybe a goalie in hockey, who never seem to be credited with winning cups for some reason (at least from what I see, I might be wrong on that). Hockey goalies and pitchers are the only single players who can dominate games and give their team a chance to win single handedly by shutting out the other team, but they still need their teams to score at least once. Anyways, my point is that you can't evaluate a player with how many titles he won. It's based off how good their teams were. It can elevate a player's status (Garnett, Russell, Elway) but it shouldn't define someone like Marino, who did everything he could to get a ring and was let down by an organization.
I notice no one ever really blames Barry Sanders for not winning a ring, and I think we should be doing that for more athletes.