That is one of the regrettable fallouts of governments covering up terrorist attacks as accidents.
Many terrorist groups want notoriety for their actions. Thus, if a government covers up an act (singular acts called accidents, bad fuel, broken fuel line, cross winds from another plane, etc.), it emboldens those terrorist groups to commit bigger and more expansive acts that are too big to be covered up and classified as accidents.
Flight 800 might have been explaned away as an accident. Was it terrorist or accident? We need the truth.
Flight 587 might have been explaned away as an accident. Was it terrorist or accident? We need the truth.
One plane hitting one of the Twin Towers might have been explained away as an accident. Two planes, much more difficult to explain away. Three planes, impossible to explain away.
I think that was exactly the point of the 9-11 attacks. There had been attacks that they got no 'credit' (ie terrorizing the populace) for as they were explained away as accidents. They were determined to make sure it was too much for even the most gullible to believe was a coincidence. After all, they did declare war on US in what - 1998.
Since we stopped the shoe-bomber, how many major airline 'accidents' have there been? None in the US? Hmmm.