How do you think?

Until then, that had never happened. Why try to get yourself killed disarming a hijacker when you know (believe) that you're just going to an airfield somewhere, wait for a long time, and then get liberated?

These people had no idea they were going to be used as a flying weapons platform

Flight 93 passengers did learn about this and did fight back, the hijacker them just flew the plane into the ground to kill them all and avoid capture

Fucking coward maniacs

The attitude regarding hijackers was different at the time - most hijackers were there for money or political stunts, often taking planes as they were full of hostages with few exits. Most of the time hijackings were not much worse than a bank robbery: starting trouble would make it worse for everyone and if you just waited it out, the hijackers would be on their way to other mischief.