Whatever their claims are, this essay hasn't made them appear less likely.
If we had had a thorough open discussion about 9/11 and the public had been made known of more information earlier, then there is a small chance we wouldn't have gone on to create the abomination referred to as the DHS.
To the extent that Truthers caused the DHS to happen, they are a deplorable lot, but their arguments are as valid (or invalid) today as they were yesterday.
Huh.