My answer is simple, Bears fans and Rex Grossman.
Bears fans? For a large fanbase, they are really under the radar. Chicago Bears fans are generally likable people. It's the Eagles, NY and Boston fans that are completely unlikable.
Rex Grossman is a product of the media trying to create a story. Many QB's have pretty bad games. Manning and Brady had horrible post-season games here and the general attitude is "They'll recover", while Grossman is met with "He'll probably blow it" or "He's a big risk". Rex is just the typical meathead QB. We went through that last year with the NFC's rep in the SB.