First off, I'll say that I loved the movie. Definitely one of Pixar's best.

I'd just like to say that to me, the "social criticisms" were more plot points than anything bigger. I just don't think Pixar was really trying to push a pro-enviroment, anti-big corporations message. While viewing the movie, I thought the main message of the movie came from the quote "I don't want to survive, I want to live!" and any circumstances beyond that were just guiding the story.