I agree. You can definitely not please everybody and there are people with unreasonable expectations. However, it is the extra mile that people remember and a token of appreciation from the line would not be inapropriate here. If it were me, being a frequent guest of RCL, I would have some expectation of the company to acknowledge that I am not getting the product I paid for even though it was beyond their control. This is what differentiates a discount line from an upper tier line. Some token, ie a $50-$100 credit on the next cruise hardly costs them anything. With all the promotions they offer, other people get them anyway without even being 'put out'.
I have sailed with RCL 9 times. I tried Princess once and will not go back. The reason is simple. When I had a problem on my princess cruise, I did not feel that I was taken seriously. A simple gesture by them might have gained some or all of the 7 cruises I have taken since. They were so dismissive of my problem that I did not even give them an opportunity to make it up to me because I would absolutely not use it. RCL has gone the extra mile for me and that has earned my loyalty.