At the time, SOP when a hijacker took over a plane was to do whatever they said. They nearly always held the plane for ransom, and it really was best to let authorities on the ground handle things. After 9/11, the entire plane's population would attack you, becuase being smashed into a skyscraper is not in anyone's best interests.

Even on 9/11 this happened. That's why the 4th plane crashed in a field. Passengers found out about the first 3, realised all bets were off, and took back the plane/