The hand baggage chaos was caused by the airlines themselves when they started charging for hold baggage - of course people are going to try and get by with hand baggage alone if possible. I never used to have hand baggage and now I am one of the people competing for overhead locker space which is quite obviously insufficient if everyone on the flight has hand baggage. There never used to be any problem finding space before they change the rules on hold baggage.
On a recent flight from Glasgow to Belfast (a ridiculously short journey, seatbelts on, seatbelts off, seatbelts back on
) easyjet announced to the boarding queues that due to the amount of hand baggage, anyone who's baggage didn't fit in the cage would have it put in the hold and charged £40. Two minutes later they must have realised they had a serious problem, becuase they announced that they needed volunteers to have their hand baggage put in the hold for which there would be no charge.
But they caused this.