I can't agree with that. Attendance-wise, Orlando already has the top two, possibly three, water parks in the country. When Volcano Bay opens next year, it's sure to join that list. Two of those--Aquatica and VB--are basically on the same street as this property (can see VB easily from I-Drive even if you access from Turkey Lake). On top of that, Margaritaville will also have a water park component open to the public.
At a certain point, you hit market saturation. Water parks is one of those things the big boys do well, better than anybody else, at a fairly reasonable price. To compete, you need to go in a different direction--thrill rides is certainly one route, an indoor park might be another. But a sixth water park will instantly turn Wet n Wild.