Regarding the OP's reference to the tourist board in Belize and other poster examples:
OK, just how do they propose to get tourist in any significant numbers to visit their areas? Build interstate standard highways, major airport facilities, or high speed railways? Cruise ships are a pretty efficient way to get large numbers of cash customers into your market.
If you can't bring in the tourists they can't spend their money in your market - it's that simple. I would think that if your mind set is that you don't want a lot of people to "spoil" your personal paradise but you do want their money then cruise ships that come in, spend money, and then leave within a few hours would be a dream come true!
Cruising allows a lot of people to travel to places they otherwise could not afford to go to and spend their money. Does the Belize tourist board expect people to just stick their money in an envelope and send it to them?