I have no problem with them adding more Toy Story to the area - it is Pixar's first movie, made them wildly successful, and broke new ground with software (and they continue to do so). It's well deserving of a section. But I will agree, if this is Pixar Land, there needs to be more. The company is about technology and bringing stories to life via some great people and that tech. Let's have more of them all represented here with their work.
Side note: Disney fans of old would argue that Walt had designed Disneyland around people, not films. The films were simply a bonus and added in as characters and rides. Seems to me he designed Main Street, Frontierland and Adventureland around people and activities we might love but otherwise not be able to experience. Fishing, a riverboat ride, walking down a road styled after the old west, and an old fashioned main street are just some of the unique aspects that stand out. This bit about designing entire areas to movies is newer than Walt, which is fine, if that's the way society wants to be entertained now. However, I'll be the first to hop up and say I'd rather have the story behind making the movies back instead of being IN the movie. But that's neither here nor there as Disney started to give up on showing us how movies are made some time ago. They're peeling that layer off of DHS bit by bit.