The idea of pax not carrying their carry-ons is only a concept. The average person would be probably more prepared to sacrifice their first born rather then be parted with their bags. Think of the palaver that check-in and gate staff go through on each and every flight with pax who insist that their oversized, overstuffed 20kg "handbag" would 1. fit the gauge if the gauge wasn't "bent" and 2. fit any and every overhead locker and 3. tell the same staff in no uncertain terms that as everybody else is taking three or four pieces, they will as well.
Now fast forward to the flight. Now imagine insisting that in the midst of an evacuation that the plonker standing in front of you (probably with a fully inflated life jacket) will have to leave their bags behind. Also, apart from the fact that they best place for their bags is now outside the aircraft (where will you put it if they hear your order and comply?), do you really think they would comply? Not a chance.
The only way would be to prosecute a few of these numpties (reckless endangerment?) and levy such swinging fines that people in the future would think twice. Would it work? Maybe. Speaking for myself, I've noticed a tremendous improvement in the behaviour of pax now that they know for sure that "arseholism" will be severely punished and will not be tolerated on our airline. But there again, maybe they are flying with the lo-cos.
PM