I'm not surprised. Making realistic graphics is a pretty straight-foward process. Cel-shading involves a lot of programming on the side to make it work.
In essence realistic graphics are easier, but making them convincing is incredibly difficult. When a game tries to immitate real life, you judge it much more harshly because you're extremely accustomed to it. You notice every little discrepancy in a realistic style, which can really bring the whole thing down. With a cartoony style, such as Wind Waker's, we don't judge it nearly as harshly and accept it much more readily. If a realistic style isn't very detailed it can fall flat on its face- other styles don't suffer from this.