The problem is, they aren't charging for just the exhibits. They are charging for the rides, the ambience, the shows, and the overall experience, in addition to the exhibits. When I visited Busch Gardens, I saw every animal exhibit and rode every ride, and I had a
fantastic time. At SeaWorld San Antonio, I must've ridden one roller coaster at least 7 times... and at SeaWorld San Diego, while I didn't have time to do the same, I still watched shows, rode rides, viewed animal exhibits, and enjoyed myself. Whatever a place charges for admission, I do my best to get the most out of it. It's not a ripoff, if you do everything offered. And if you don't make full use of your ticket, then why did you go? Everything is worth trying once.
@pachyderm pro: I recommend visiting, at least once, as I do with most zoos/marine parks/aquariums. The penguin exhibit is considered the best one in the world by many who have seen it. I spent over an hour in that room, photographing and watching their antics. It is the only place in America to see emperor penguin, and one of two to see Adélie. Think what you will of the cetacean programs. With marine mammals, though, this SeaWorld surely has the highest diversity. I think (I could be wrong with this) that their Guadalupe fur seals are the only ones permanently in captivity, anywhere. Certainly the only of their kind displayed in America. Southern sea otters aren't too shabby, either...
And then, of course, there are the aquariums. A forgotten part of SeaWorld, but in San Diego there are a few separate buildings. One focuses on sea turtles, and anther entirely on cephalopods. There's another focused on sharks, and at least one more with a higher variety beyond those.
So, choose what you will, but I think that not visiting at least once is a big mistake. Don't forget, either, that some of the museums near the zoo in Balboa Park are also worth a visit. But it's your trip.