It's right up there with the New York City valet Superchargers. W 75th Street, for example, is $35 entry fee for earlybird parking (least expensive option). It goes up from there, with the minimum daytime fee being $39 for 30 minutes and $49 for an hour in the evening. Kahala at least offers validation if you spend money inside - like enjoying lunch while you charge.
This certainly isn't going to serve the charging needs of the general public. However, it does support travelers who are looking for a boutique experience. Tesla rentals are very popular, and this gives people a chance to recharge and explore the resort instead of waiting for hours at the other Supercharger.