I guess I see how something like that could be convincing to those willing to buy in. And, that leads me to my question. Why are so many people willing to buy in?
That is patently obvious, calamity. Most Americans are brainwashed, the US propaganda was world class, as US propaganda has always been. Americans are conspiracy theorists by nature plus USians always want to believe, from their brainwashing, that there are people out to get them. And the only one that can save them is their currently in power US government. Hence all the USA illegal invasions of sovereign nations.
This is why most Americans still believe in the US government official conspiracy theory [USGOCT], the crazy one about the 19 Arab hijackers, OBL, ... .
There have been many apt descriptions from the people who have so far replied to your initial post and they are all self describing.
Still, the majority of Americans believe in the USGOCT, a conspiracy theory for which there is zero evidence. A conspiracy theory which contains myriad impossibilities that quite simply make it impossible for any sentient human being to accept.
Let me give you some:
1. US government/US military 1990s developed nanothermite. No one else in the world knows how to make it. It was discovered in WTC dust, along with about 6% of WTC dust being iron microspheres - that's a huge volume of iron microspheres as there was a huge volume of dust that was created by this "new generation of super explosive nanothermite.
2. There was molten/vaporized WTC structural steel [temps requiring 2800F/4900F+] an absolute impossibility for the only fuels available to "hijackers", ie. jet fuel and office furnishings - max temp 1500F.
Just these two things illustrate that those who believe the USGOCT are the conspiracy theorists in the pejorative meaning that it has come to hold.
It still has a neutral meaning - many legal investigators are conspiracy theorists and they envision many different conspiracy theories in their day to day work. Here are a few more totally impossible things that sink the USGOCT.
3. WTC 7 free fall; 2.25 seconds, 105 feet, 8 storeys
4. The twin towers accelerating collapses. Not possible without a controlled demolition. The USGOCT goes against the laws of physics.
5. No one serial numbered part of the roughly 4 million parts of the USGOCT's 911 planes has ever been positively IDed as coming from any of the alleged planes.
"Conclusion
The government alleges that four wide-body airliners crashed on the morning of September 11 2001, resulting in the deaths of more than 3,000 human beings, yet not one piece of hard aircraft evidence has been produced in an attempt to positively identify any of the four aircraft. On the contrary, it seems only that all potential evidence was deliberately kept hidden from public view. The hard evidence would have included hundreds of critical time-change aircraft items, plus security videotapes that were confiscated by the FBI immediately following each tragic episode." Col George Nelson USAF. 
