[GeorgeWashingtonsGhost]

Because no one expected the assault. Now with hyper-vigilance in various scenarios, a ‘rush’ is more likely. An aggressor on an airplane is now QUICKLY met with group attack because people are ANTICIPATING such a thing can happen.

[kabar]

Not the same thing. This guy was spraying people with bullets. He wasn't trying to take over the theater or promise everyone that nothing would happen if they followed instructions. There was no dialogue, just a hail of bullets and death and destruction.

You saw what happened at Ft Hood. When you are unarmed, your instinct is to seek cover and escape any way you can. It is not to charge into the teeth of blazing gunfire.