I'm another one who is not a fan of water parks, but that's because I don't swim. I have been to Wet n Wild, once, many years ago, because I had a company picnic there and got in for free. Was not impressed at all. I don't think Universal needs to blow a bundle on a water park, but they sure do need to update WnW, and please, ADD SOME SHADE!! That was the one thing I hated about the place, no shade for a non-swimmer like me. I think I went on the lazy river, and the speed terrified me.
The only water park I ever really enjoyed was a place called Pleasure Island, somewhere in Michigan, and that was because, instead of the water slides ending in a pool that freaks out someone like me, you ended in a trough, with no chance of going underwater, getting water up your nose, etc.
I think to really attract more than the usual people to a water park, you have to have land-based activities for non-swimmers, like mini-golf or something. And SHADE. And decent food.