He may not want to, but he also wants to live.
Hmmmmm. What increases his odds of survival more? Taking the fall for 0bama, or clearing the way for Biden to select Hillary!™ to be one heartbeat away from the presidency?
And if Rahm were freed up to go back to the Congress to enable Red Nancy and her ilk, he would have real power.
As it is, he's a glorified errand-boy and think-helper for Obama. He's staffed for the Clintons, and I'm sure it wasn't all that great a gig, with Slick getting impeached and both of them always sucking all the oxygen out of the room as they labored ceaselessly to build their political-dynastic cult.
Working on other people's problems, versus being other people's problem. No-brainer.