He didn't crumble, that's about it. Any success he had was because Green Bay had not game planned him at all. He's in the same vein as Curtis Painter and Matt Flynn. He's Ronnie Price as your starting PG.
And what makes me sure they're done? They're in the same division as the Packers and Lions, and would finish below at least 3 of those teams (Packers, Niners, Saints are a lock pending a total disaster) with Cutler in good shape. Atlanta, Dallas, and the Giants are nipping at their heels and getting better, while Detroit is healthy, explosive, and should generally be trending upward while they have the same record and have split the series.
It's a tight race. Trying out a terrible QB is throwing a game away that probably means the playoffs. If Hanie sucks, Orton will still need time to adjust (even though Orton is simply the better player).
$3 million is chump change and far less than what they stand to lose if they lose two in a row with Hanie.