Most passengers are untrained. The conceit that you can somehow mind control everyone to follow all instructions During An Emergency is rubbish. If you give the instructions to leave the bags, and most people do and some don't, you are ahead of the game. Human Behavior 101 would be worth a review. Then study up on Human Behavior during crisis/emergency and (as pilots) you will be aware that a variety of things change to everyday people. Some keep their heads, some don't.