People were so naive back then. They still are, but back then hardly anyone knew anything about what our government was up to. If you suggested to someone back then that there was more to the story than Muslim terrorists attacking us because they hate democracy or whatever, you would have been treated like a mental patient. If you suggested that our government wanted this to happen, you would have been called a traitor.
Nowadays I think a lot more people have woken up to what is going on. Not enough to stop these monsters from executing their plans unfortunately, but enough that a significant portion of the population will react to these events with skepticism. Hopefully more people wake up and realize that the United States government and the people who control it are evil. When enough people recognize the evil maybe we can stop the evil.