Problem with Royal Caribbean cruises?

You may or may not remember me mentioning before that one of the things I like to do after I've booked a cruise for someone is to give them a call when they get back from said cruise just to make sure they've had a good time and that nothing went wrong.
It's also useful in finding out what the different cruise lines are up to onboard and which lines are best recommended to different people.
I was making one of these calls today when my passenger highlighted what he thought was a major flaw with Royal Caribbean.
But what do you think..........?