The big ship cruises are designed for people who like to say they have traveled outside the country, but are afraid of foreigners and their weird food, languages and cultures. They also allow people to gamble in casinos where the odds tend to be far worse than Vegas and to overeat.
The food is excellent. My Mercedes Club used to be able to wangle an invite to the Cruise Travel Agents free in-port tours, which included a really great meal.
I have been on one cruise to Grand Bahama, which was pretty boring. The casino there was the most unpleasant public place I have ever been in. The people exchanging chips were on platforms 4 feet higher than the main floor and there were cameras everywhere. The idea of being trapped on a boat for a week or two does not appeal to me. I prefer to travel with the locals, eat in the local restaurants and stay where the locals stay. This rules out the smaller Caribbean Islands, because all the hotels are for tourists. You can travel to any point in Barbados from any other point in several hours, so there are no local hotels. Tourist hotels claim to be "reasonably priced" at $100 a night. Hotels in the Dominican Republic where I go range from $15 to $32. Of course, there are tourist hotels everywhere.
I suppose to really visit the smaller Islands, you would need your own boat.