What are you people talking about?
Monsters University was amazing, I give it a 10/10. I laughed, cried, and reminisced so much while watching it. It took me right back to my childhood, and that was an amazing feeling. But seriously, the animation was top-notch, the story (although some-what predictable at earlier points) has some very unexpected twists and turns. And it has some very cute and important life lessons. It is a fantastic film, and I really want to watch it again.
And as for the somewhat-negative ratings, I think this really puts it in perspective.
http://golf-echo-romeo-tardis-umqra....-a-film-critic
Apart from Cars 2, (and arguably Brave---although I loved it---) Pixar is still as iconic, as they ever were.