Again they’ve been conditioned since birth, just like the folks on the planes that hit the Towers and the Pentagon. It was a miracle that Flight 93 had a few heroes aboard.
Actually, I honestly think that if the first two flights knew about the outcome (suicide rather than negotiation), or if Flight 93 had not known the results of the first two planes, they may not have reacted as they did. Once they knew they were going to be used as a huge suicide bomb, rather than bargaining chips, they chose to do something about it.
Prior to 9/11, the response was to sit down and wait for their demands.
Up until 9/11, if your plane was hijacked, it would have been landed at a airport, you would have been part of a standoff with authorities, but 99% of people on the plane would have lived through it.
It made sense for them to just keep their heads down.
Flight 93 was notified by various phone calls that other planes had been used as weapons to attack buildings. The people on flight 93 were aware that the rules had changed that morning and keeping your head down was going to get you killed as opposed to keeping you alive.
There were heroes on the other planes too, but they weren't aware of the rule change in time.
These kids have had the "fight" worked out of them in the "fight, flight or freeze" response. In the U.S. you likely would have seen a few "fight" responses and this may have ended minutes after it started,