Disney wanted to include everyone in his vision of animation.
If you talk about God, you are excluding folks who do not share your conception.
All of the world's religions are about good versus evil and one of the great achievements of Disney movies is that they have crossed all religious and international boundaries.
On the other hand, if you look at the TV shows that always mention God (or more accurately, always mention one religion's view of God), you will find a much smaller viewership. Additionally, it is probably a viewership that is already sold on the message. If you don't believe me, watch a relgious channel devoted to a different religion.
In my experience (and I consider myself a believer), people who need to see God mentioned all the time, haven't really discovered Him.
You only know if you are true believer, in my view, if you can leave your comfort zone. When you do this, you will find that your faith is stronger (at least, that's been my experience). And, if you have the same experience as me, you will love Disney movies even more. :-)