Your analogy to aquatics is interesting but doesn't hold water, if you'll pardon the pun.

Firstly, you can get a couples swim membership as well as family and individual. You can not get a couples membership in racquet sports or any single racquet sport.

Secondly, you are paying by what pool you use in that there are summer, winter and yearly rates in all three of the above categories so  there are 15 different rate packages available. To use your thinking aquatics should only be offered as a yearly membership and a person who says I don't use the sports core pool in winter so I shouldn't have to pay for it is out of luck.

Lastly, the just of my point is that it all comes down to budget dollars and how we cover costs. OP can always jack up rates but how about tying them to the actual operating costs and make use of some simple technology to bring those costs down. A swipe/payment kiosk would do that and everyone would be happy and pickle and platform could still support tennis when the numbers are rolled up for the racquet center as a whole. Tennis has higher operating costs and only 50 members anticipated in the 2026 budget. 

An automated system for beach parking would also make sense . Ocean City no longer has parking attendants at the huge inlet parking lot and no attendant at their Racquet Center  pickle/tennis (clay) courts for 8 months of the year and guess what? You are welcome to use them free of charge for that period.