I can tell you from a Delta perspective. You open a crew base for two reasons. A reduction in credit hours and or an improvement in operational statistics. Hotel costs can be a third but minor player. HNL because all legs are more than 5 hours block to get there offers little in the way of credit reduction. In fact it likely increases credit because long legs make it much easier to build low credit rotations. Pull those long legs out of domestic bases may increase their credit. Operationally you also gain virtually nothing. With the weather in HNL and a predominantly one way traffic flow irops requiring reserve crews are non existent. In short a HNL base for airlines like Delta or UAL probably increases costs.