I think his legacy is extremely important to Rodgers, and I think he knows there's a good chance that he only has one more season to win that second ring. If he's truly waiting for some contender to lose their starting QB to injury, he's taking a huge chance.
There are only a handful of teams that are serious Super Bowl contenders, and sitting on his *** hoping one of them will break their quarterback is an enormous and frankly foolish gamble. He's no longer a guy who can carry a mediocre franchise on his back, but with the right team, I think he can still be a Top 10 QB - it's not a stretch to say that he could be the missing piece that Pittsburgh needs to become legitimate contenders. I think his chances with the Steelers are much better than the chance that one of 6 or 8 other contending teams will lose their quarterback after the season starts.