Sometimes more can be ascertained from the mistakes of a plan, than can be from its successes. Flight 93 was not meant to be shot down, but it was. And what ensued in the aftermath of that action, quite literally, exposes the criminals of 9/11 more so than does any other single aspect of the case, simply because of what the conspirators had to do to cover it up.
Imagine for a moment that the “conspiracy theorists” are correct. Or should I say the “alternative narrative” theorists are correct. All of a sudden, the criminals of 9/11 are staring at radar screens showing their final act in their carefully planned production, lying in ruin in Shanksville Pa. and they still have a 47 story tall building, barely even on fire, completely wired with RDX, TNT, and PETN… ready for demo.
All dressed up and nowhere to go.
I think this is a very plausible theory.