Well yeah, that's what a lot of people usually think, but big companies like Disney probably use a degree as a way to weed out those they think aren't experienced enough to direct the next big Aladdin movie or whatever's animated nowadays. They probably look at degree holders before they look at everyone else.
They look at portfolios above anything. But grades do have a little bit to do with it. No company is going to turn down an amazing animator or whatever just because they don't have their masters in something. But no big company is going to take a good animator who can't pass his grade 12 classes. It also depends on how big the company is I guess. And how diverse or specialized your classes are.
If you want to be a graphic designer and you have taken web design and package design your chances are probably better than the guy who only took graphic design.
It's like that in any sort of art. Freelance is completely different though.