I've not personally heard a single person blame GWBush for the attacks. I've heard people try to blame Clinton, or BushSr., or both--rightly or wrongly on both. I've heard a lot of people (again, rightly or wrongly) blame GWBush for the way he has responded to the attacks 9/11. And I've heard a lot of GWBush apologists (wrongly) get upset at those people and claim that they're blaming GWBush for the attacks, when that couldn't be further from the truth.
C2, your statement about the passengers on the planes is ridiculous nonsense. Never before had hijackers taken a plane and used it as a weapon. Those people in those planes had no reason to suspect that would happen. In most hijacking situations to that date, the plane has landed, the hijackers held hostages and made threats, and the situation often came to a conclusion where some if not all of the hostages survived. Outside of hijacked planes crashing unintentionally into habitated areas, I don't believe a hijacking had ever previously led to loss of life of civilians outside the plane. There was no reason for them to suspect that this would be any different--and therefore, they're best chance of survival was to sit quietly, do nothing, and wait for things to take their course. The passengers of Flight 93 would likely have done the same thing, and rightly so, if they had not received outside information that prompted them to do otherwise.