When it comes to animated movies, the studios are all about producing sequels because the movies they're based on already have a proven track record and it's an automatic fan base. Not all of those sequels are worthwhile. I saw "Despicable Me 2" and "Monsters University" in the same weekend and weighed in on what I thought of them compared to each other and the original movies:
http://www.bsckids.com/2013/07/geek-girl-navigating-the-world-despicable-me-2-vs-monsters-university/