Many pilots and tv shows are created by virtually nobodies just because the network heads believed in the project.
Take, Adventure Time. Pen Ward had nothing to his name except that little pitch book and a CalArts degree. And pretty much every fucking aspiring animator/cartoonist living in California has both of those.
Justin Roiland was only known for his SCREAMING!!!! voice. No one except Dan Harmon watched his shitty animated shorts that he made in 2 hours. No one was commending him for his writing skills on Fish Hooks. But Harmon believed in him not for his credentials but for his humor and now R&M is a hit.
Sugar, in comparison, was almost entirely riding on the coattails of AT's success.
I'm not saying Sugar is a unique incident, I'm saying the animation industry has a lot more examples of artists being given a chance than other entertainment-based fields.