I can only answer this question if I am told what are the infallible testimonies proving that 9/11 was an inside job. I do not doubt that Bush, Cheney and Rumsfeld are a gang who could do it for promoting their belligerent intentions, but I see no proof that they did it. The infallible proof, thus far and as far as I know, is mere conspiracy theory that stalks every incident of violence.
On the other hand, if you tell me that Osama Bin Laden was a mere scapegoat, I am inclined to agree with you. There are many reasons that could be deemed infallible, unless proved by other circumstantial evidences, to believe that Bin Laden had nothing to do with 9/11, except perhaps that he tacitly owned up responsibility for the glory of it. There were many Saudis, far richer than the isolated Bin Laden, who were extremist wahabis to fund the training and logistics of those four fanatical idiots who commandeered the flights. Those Arabs are still laughing in their sleeves, doubly glad that an innocent (in this case) erstwhile friend of the United States is being nibbled bone-bare by eels and urchins under the sea,