I still wonder why planes don't come with safety measures like when things go wrong, roof disconnects and all passengers are ejected buckled to the seats with parachutes that would automatically dispense and at least give people a chance to survive. Have a homing signal on all the chairs...is it really that hard to put all this technology together to avoid these kind of things? I'm not buying terrorists yet, especially with nobody claiming any responsibility. Like I posted earlier, they typically want to make a big spectacle over land and not just sink something way out at sea.
Price of such a system, weight issues, space of the chute packs, breathing apparatus (clue, you eject at 35K feet, you are dead in a few seconds from cold, lack of oxygen and injuries from wind blasts going 400 mph or more). Really, unless there was a system to eject the entire enclosed cabin, this isn't remotely practical.