Where does all the tourism money go in the Caribbean?

I've been to Aruba, Antigua, St.Lucia and other islands in the Caribbean, and I know there are a lot of people spending money on tours in those islands, on the days their cruise ship is in port. And there are tourism shops at every port. So my question is, why is there so much poverty in places like St. Lucia and Aruba, can't they distribute the money so that no one has to go barefoot or live in a tin shack?