Carry-on baggage limits

I am a reasonably frequent international traveler who flies economy and not business class. What really irks me about economy is the inability of the airlines to police carry-on baggage limits. I arrive at my seat and all the overhead lockers are stuffed full of hand baggage, the fight for space slows down both boarding and exiting the aircraft.

Everybody knows the hand baggage limits and a large majority wantonly abuse the limits inconveniencing fellow flyers. Fortunately, my carry-on luggage is below the 7kg weight limit and well under-sized so I can stow under the foot rest of the seat in front of me. Really, it is up to the airlines to enforce these rules to ensure self-centred and arrogant passengers do not ruin the flight experience of fellow passengers who actually do the right thing. The airlines need to get together, this is currently being abused by way too many people.