I'm expecting flack, but I'm wondering how many others really didn't like Pixar's Up.

Watching it the first time, I enjoyed parts (the opening scene is gold), but for the most part I was just mad at how Carl and Russell came out of nowhere and completely ruined Charles Muntz's life's work. With complete disregard, they float in and find what he's been searching for most of his life by complete accident. It feels silly, but I couldn't help feeling sorry for Charles. Sure, he's a hunter of exotic animals, and he may not be the nicest guy on the planet, but come on. Why is it alright for Carl and Russell to ruin everything just because they think they're doing the right thing?