Let's be fair here. There are a lot of nice people that take cruises. I have taken cruises, see that proves the point. Seriously, it is not the person taking the cruise that is the problem. There are a lot of destinations that have made that "investment" and provided for the cruise business. Belize has not. Just having a dock and a tourist village will not make Belize what it needs to be in order to handle cruise business.
If you throw a party at your house and invite a bunch of guests and do not have the facilities to handle them, it is not the guests fault.
Banyan Bay is a good example. It started out "hosting" the cruise people. It did not take long for the overnight guest's complaints to make the management realize it could not have it both ways. It realized the guest staying there was more important than the cruise business. Belize and all it's businesses need to make a choice.