My sense is that so much of the truther mindset comes from the fact of distrust of official statements... and this includes gov and media. Media is doing a lot of "stenography"... ie simply reporting verbatim what officials tell them in press releases or conferences. There is little to no fact checking... or real reporting to discover the facts. It's cheaper and easier for the media simply to repeat official statements. The DOD has also taken to produce "media stories" which sound like news, presented like a news report, but are essentially manufactured (dis)information. We live in a world of PR and spin because institutions need to protect their franchise, the budgets, their agenda and so forth. Media companies are "for profit" as well and so news has morphed into "infotainment".
Then of course you have the deal with the notion that people who commit any sort of wrong doing or incompetence do not want to be held accountable. The justice system seems to be over bearing on the poor and and least powerful elements in the society and those at the top (and law enforcement) seem to escape accountability constantly... such as the wall street failures, the police shootings or Fukishima, the Hubble telescope mirror, or the CIA for torture to mention a few examples. The truth may leak out even years later.... or not.
So many people are aware of a pattern... Media spinning and no accountability for both wrong doing and incompetence. This includes waste, fraud and abuse... Why would ANY major story not have the same elements... spin, deception, protection of franchise, no accountability and so on? Wouldn't that be the exception and not the rule? In fact... are there any exceptions where the public got the unvarnished truth and there was accountability as one would expect under the "rule of law"?
With respect to 9/11 there is no reason to think that the official accounts are not laced with spin, PR CYA and so on. At the very least whomever did 9/11, the apparatus we were told existed and paid trillions for did not prevent or stop the attack in progress. Our national security state was a failure. So at the very least we saw no accountability for this at all. At best we hear that the intel didn't work because of walls and competition between intel agencies. And if this were true... it was "congress" which set up these systems of intel... Can you imagine anyone being held accountable for the creation of the flaws in the national security state? Hell no. Of course the truther will then jump to the conclusion that nasty "insiders" were able to EXPLOIT this flawed structure to stage 9/11. But why? They then jump to the conclusion that these nasties wanted a war, wanted to increase surveillance on the people, and gain access to the spoils of war... resources and control of the region. This clearly appears to be a motive of powerful extraction industries and suggests that these industries were able to control or had agents inside the government who steer policy. Everyone is aware of the on the radar activities of lobbyists who essentially openly are able to manipulate congress critters. This happens all the time to the betterment of the powerful and the detriment of the people.
What does seem to be missing in the truther based analysis... is the notion that the MIC, the corps, the powerful... the "US empire" has riden rough shod over people around the world and that those people will not, cannot strike back in any manner. For sure the disenfranchised don't have fighters, bombers, battle ship groups, ICBMs, even drones (yet)... and so all they do have is asymmetrical warfare, or as the MIC calls it "insurgencies" ir the tactic of terrorism. Terrosists don't need to engage in military battles to defeat their enemy and stop the oppression. They need to "freak out" or terrorize the public so that they demand policy changes. The notion is that the public will recognize that they are unsafe, that this was the result of failed policies such as what the empire routinely does... oppressive militarism... carpet bombing, land mines, white phosphorus, cluster bombs, destruction of infrastructure and so on... not to mention propping up oppressive and repressive leaders who do the empire's bidding.
There is more than enough justification for an explanation that 9/11 was a case of blow back... disgruntled groups who staged a terrorist attack and one that the existing national security state was not set up to see coming or stop in progress. It was so low tech... that intel's spying was able to be gamed... and missed it except the so called chatter that something was afoot.
break... more to follow