I think the biggest problem Cousins has is the perception curse. He put up some great stats on a bad Redskins team, so he's a "stat whore than can't get he win"...but, most of the stats happen over the course of whole games. They kinda forget that.
Then, it was his primetime record. Hey, we know about that...and he's now won on Sunday, Thursday, and Monday night games.
He "can't get his team to the Superbowl". Folks, our conservative-as-f**k head coach, our line, and our patchwork defense are far bigger obstacles than Cousins is.
He's a genuinely good QB that plays in an era of some genuinely great ones, and nothing short of a championship will get him credibility with certain people.