C'mon on now, I know fans are prisoners of the moment but you don't remember 4 fights ago when he took on Griffin right after
Griffin lost the title. He then decided that he was to good of a friend to Machida to fight for the title.
Shields has beaten Okami, Miller, Lawler and Henderson, he also has the longest win streak(2,500 days) of anyone else on that list and if he beats GSP he's likely going to break Fedor's record of 3,500 days without a loss.
BJ was on the list because he held titles in both classes and was the only LW in consideration for the p4p list.
You also forgot Jon Fitch who's on the list.
As for fighters who didn't stick in weight classes that they were winning in IIRC Vera 8-2, Sanchez went 2-1, Belfort...5 or 6 and 1 before the catch weights and middleweight fights.