First of all as someone who has left stuff behind, it sucks. I have always felt that I deserve half the blame. BUT there is no excuse Royal Caribbean to be rude. We had damaged luggage on Carnival, our first cruise. I gave up complaining when I kept getting no response.
Last Oct we were on Oasis of the Seas. As we were leaving an attendant opened several rooms. These rooms were nicer than ours and we stepped inside and looked around. Only after about the third cabin did someone see us and tell us we really shouldn't be in there. We told them we were just checking out the cabins for our next cruise. He said ok but we really should not be in the rooms. Trust me when I say we were in there before any attendant!!!
But again that does not excuse RCCL from being rude. I'm sure they deal with thousand of issues every week you would think they would be better at it.