The question is, why do people adopt and internalize whatever story is told by authority figures, and toss put-down comments at anyone exercising critical thought?
The thing is,
a) voluminous credible evidence exists that the official story is untrue, not shouted by feeble minded cranks, but given by eyewitnesses, and by prominent, critical-thinking experts. For example, lots of firefighters and rescue people testified they actually saw bombs detonating at WTC (flashes). Another example, it's patently obvious no Boeing 757 hit the Pentagon. You must already know lots of other examples.
b) It's a fact there have existed false-flag plans to incite the lethargic public to war by self-inflicting damage onto our country, e.g.; Operation Northwoods. Reasonable minds wonder if 911 may have been the actualization of some zealot plan like that. Maybe yes or no, but it's a fair question.
c) It's a fact that Dick Cheney and Donald Rumsfeld were founding members of, and committed to, Project for the New American Century, which openly advocated use of military force to establish what they call 'Pax Americana' to dominate the entire earth. PNAC openly discussed their desire for a "new Pearl Harbor" event to convince Americans to go to the war which PNAC advocated.
It's understandable why our moderators are forced to lock threads attempting to discuss this, because mods have to make sure posters don't just shout at each other from closed-minded dug-in emotional postures. Seems like folks tend to get that way on this topic. Several posts above are perfect examples of this.
Unfortunately for the rest of us, that shuts down valid, even-minded, rational discussion about the questionable official story.
?There was just an explosion [in the south tower]. It seemed like on television [when] they blow up these buildings. It seemed like it was going all the way around like a belt, all these explosions.?--Firefighter Richard Banaciski
?I saw a flash flash flash [at] the lower level of the building. You know like when they demolish a building??--Assistant Fire Commissioner Stephen Gregory
?It was [like a] professional demolition where they set the charges on certain floors and then you hear 'Pop, pop, pop, pop, pop'."--Paramedic Daniel Rivera
Russ Wittenberg, who flew large commercial airliners for 35 years after serving in Vietnam as a fighter pilot, says that it would have been "totally impossible for an amateur who couldn't even fly a Cessna to maneuver the jetliner in such a highly professional manner."
Please read this transcript, directly on point of your OP question:
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And this one too:
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