My major argument against "Bush did 9/11" is that I think he and his cabal (probably) lost money/power in the balance. Even if that wasn't true, a good risk analysist would point out that there was no guarantee that things would work out the way they did. What if congress hadn't authorized the war? What if Syria and Iran had enjoined the conflict on the side of the Shia? What if Cheney had died of a heart attack?
Then there's what Noam Chomsky said, "One of the major consequences of the 9/11 movement has been to draw enormous amounts of energy and effort away from activism directed to real and ongoing crimes of state, and their institutional background, crimes that are far more serious than blowing up the WTC would be, if there were any credibility to that thesis. That is, I suspect, why the 9/11 movement is treated far more tolerantly by centers of power than is the norm for serious critical and activist work."