The information in those demonstrations is trivial and hardly helpful once put to the test. People will panic and that means that little boring sermon will mean almost nothing where it counts.(as always happens)
Perhaps we should be campaigning for people to undergo aircraft-emergency simulations?
You're right that people panic, but people only panic because the situation is unusual. If people regularly experience "emergency" situations without the danger/fear (especially throughout childhood), they can be trained in what to do enough that handling a real emergency becomes routine and practically instinctual.