Every airline I've flown on has made the restrictions on hand baggage quite clear - if you don't meet those requirements, that's your fault. Doesn't matter if other people on the flight "get away with it" or "it was alright on the way out". Take some personal responsibility.
Airlines and the rest of the airline industry regularly tell is that "safety our first priority" so I can't stand the hypocrisy of allowing bottles of duty free in the cabin.