It's a little bit sad. He was rewarded so early for an amateur work that he never had any incentive to develop his skill further, unlike peers who didn't get publishing deals on their teenage crossover fic and spent the next decade studying creative writing and honing their abilities. Sure, he could've decided to use the opportunities Eragon bought him to improve, but it would've first required him to recognize that writing lauded as "good for a teenager" isn't a level you want to be at when you're in your twenties and thirties.