Catamarans will appeal to charter guests who like the idea of sailing but would prefer not to heel over. Catamarans have two hulls and are therefore able to maintain a level sailing pattern and these hulls will also have shallow drafts which means they can sail in shallower waters.
In layout terms they generally have extensive deck areas and the newer models also have an upper or flybridge deck and it’s not surprising that they have become the dominant type of charter boat in some areas - such as the Virgin Islands.