lol we gave a narrative compulsion to a character who had a drive that was largely centered around not wanting the responsibility and fear of failure.

They seem to have forgotten that Aang was barely a teenager when he was told "Hey, kiddo, you're the chosen one!" "So you've gotta stop being a kid and be an adult immediately."

Then later learns that him doing what makes total sense (and is objectively a correct action) as a kid, not wanting to take on the scary responsibilities of adulthood when they're still literally a child, winds up with everybody/thing he remembers with love and fondness were brutally destroyed.