|One of the most remarkable facts of that day was how quickly their model fell apart--forever.|
Their model(of taking over a commercial airliner and using it as a weapon)depended on the bias of all of us to regard hijackings as almost scripted events: they will fly around, land somewhere, make demands, and then use the hostages as bargaining chips.
The people hijacked in the first two planes were still influenced with that long standing bias, and succumbed to it. But because of communications technology, the word of what was happening reached some in each of the other planes; there was even some evidence that there was beginning to be awareness on AA Flight 77 just before it hit the Pentagon; already, the bias was crumbling.
By this time, the folks on United 93 knew enough to totally shatter that bias; it was officially gone forever, and those passengers acted rationally.
The next nutjob who stands up in a flight cabin to take over a plane will literally be torn to shreds by rational people using nothing more than their bare hands. The days of passively hoping for the best and conceding planes to nutjobs is also what died on 9/11. Never again without a fight to the death.
Their model lasted not even for one hour before it was null and voided, made obsolete forever. At about 9:30am on 9/11, 40 brave passengers declared, forever, 'Hell, no,' and 'never again.'