Anthony C , if the rugby team six footers cannot get access to the flight deck, ( armoured door), then I doubt that they are going to be able to hijack the aircraft.
One of the things that 9/11 did was redefine the value of the passenger load vis a vis say, the World Trade center, or what have you, and since that event I would venture to say that they, (pax load), are considered expendable. The fact that the USAF is ready to be used to prevent a repeat of the WTC destruction would seem to bear that out.