Pretty sure the actual economic damage ($250B) from 9/11 attacks was small compared to the self-inflicted economic damage that followed in the form of market reactions $1T and wars $2T.
In other words, "the only thing we have to fear is fear itself."
Factor in the two wars and you’re talking a further 6+ trillion. Call it self inflicted or not, it seems disingenuous to act like it all wasn’t a direct and predictable result of the attacks. I’m not discussing blame after all, but consequences and what poeple reasonably fear.