Priority Service.
When working probably, it gives priority to YC guests when an elevator is called.
If the YC beach was closer, it would be more likely to be invaded by interlopers. As for the rocky beach, it wasn't always that way. A tropical storm undid all of the work that MSC did on that beach.
I'd rather have excluded and rocky instead of crowded and smooth.
Bimini Beach and Paradise Sands (adults only) are farther away but are also very nice. I'd have no problem if the Yacht Club took over one of those areas.