In the areas of the Internet that I frequent, I encounter anti-DreamWorks Animation sentiments, while Pixar seemingly (and unfairly) receives a free pass.
No one ever trumpets the existence of Cars, or that Pixar's next two films are Toy Story 3 and Cars 2 cash-grab sequels.
No one ever notes that A Bug's Life and Monsters, Inc. are utterly forgettable (probably, to be fair, because they're so utterly forgettable). When was the last time you thought about either film?
No one ever brings up how WALL•E devolves into fatties discovering environmentalism, or how Up is hijacked by annoying animals that exist primarily to pander to children.
At least DreamWorks doesn't pretend that its animated films are anything besides commercial trifles.