If everyone took more carry on luggage than allowed, where would it go. Last year I was sitting at the front of the plane in the bulkhead seat, so one of the last to get on, the overhead lockers were full and my bag had to be put in a locker near the rear meaning I had to wait for for all passengers to get off before I could get it. Have you ever tried moving along the aisle once a plane has landed.
I've no problem with elite getting extra weight but put it in the hold.