Bush understood, and Mitt understands, that Osama became irrelevant except for being a potential cheap political point. Many were distressed when he said that getting Osama wasn't the hottest thing on his plate, but he was absolutely correct. All the trash surrounding Zero's part in it shows that while he tried to leverage it for maximum benefit, all Zero did was turn Osama into some corny catch phrases like "Osama's dead and GM's alive". Rely on childish catch-phrases long enough and they finally make it clear that it's all you have in your arsenal. Mitt and his have done well to leave it in the background while the Left tries, ineffectually, to capitalize on it.
I agree with you on the shallow narrow politics of the moment, but I profoundly disagree on the bigger picture. Just like the economy in the ditch, the causes are all liberal and the solutions all conservative. When we ignore these truths in an attempt to sneak through a debate, we weaken our ability to actually correct the problems in the long run. It was Bush Cheney Rumsfeld conservatism that led to Osama’s killing, period. Obama liberalism stood in the way, before he finally carried it out. Truth matters.
But yes, you did point out the purely political calculations Mitt made.