Looks like RCI has thought of another way to make money.
Let's speculate on how this developed. Does anyone think it started out by someone saying "what can we do to make things more comfortable for those with late flights?" Or perhaps it was "we can make more money by selling a late departure option to those with later flights." But then it doesn't matter, because if the first option happened it was followed up with someone else saying "yeah, and we can charge them for it too!"
This is an example of a thread that nobody will remember when they instead claim we are all cheerleaders for the cruise lines.