I thought Aang just wanted to have fun and see the world originally and did not like the fact he was forced into being the avatar. Because of that he was delaying his duties with personal desires and fulfillment, more so earlier on in the show while he was still grappling with being the avatar.
Reminds me of my problem with the movie of The Martian (which I did very much enjoy). The book is the main character having one thing after another go wrong. The movie is the main character’s triumph over obstacle after obstacle. I’m not sure what made them seem in this way though.
I think it's due to how knowledgeable, practical, and yet pessimistic Watney's inner monologue is through the book. It's one thing to see something go wrong on screen (they did show all of the major issues as far as I recall, and a few minor ones too), it's another to have the main character scientifically dissect exactly how fucked he is or will be if the next attempt at a solution fails.