Well, if you were the President, would you have killed Bin Laden in the middle of the revolutions in the Middle East? Wouldn't have been very good timing. Might have hit the reset button on all that. Much better to let it run its course. Bin Laden wasn't going anywhere. Not with the Pakistanis having him so well controlled.
Bin Laden knew it was over for a long long time. According to reports he didn't leave the compound for five years. He probably couldn't get out if he wanted to. He didn't have Internet or phone service. His only connection to the rest of the world was through a courier, and we knew all about that. Did Bin Laden know we knew? I think so. And there was nothing he could do about it. The man was cornered. And he was that way for a long time.
Using an Occam's Razor approach, the deal he had with the Pakistanis and the US probably went something like this. As long as there are no major acts of terrorism in the west, and as long as we don't need you to die for some greater political purpose, you get to live. But you have to stay confined to this prison, with one wife and a few kids, a vegetable garden and reefer. Bin Laden's life was a chip that could be cashed in for political gain when needed. On Monday the clock ran out for him.
Not sure I believe it. But thought provoking, none the less.