That guy told his firstborn that he was "lucky to be born", maimed his son's face in cold blood because he spoke out of place, and then exiled him to a wild goose chase. His endgame was to literally burn the entire earth kingdom. What redeeming cualities did you expect him to have?>>108082841
I had completely forgotten about the dialogue of the coronation, but there's a scene where Mai meets Zuko when he's getting ready for the coronation. She says that "his uncle pulled some strings" and that "it also doesn't hurt when the new fire lord's your boyfriend". And he's clearly happy about seeing her.
We also see that before his official coronation most of the war prisoners that participated in the eclipse invasion have been released.
We can only imagine what happened in the time where we don't see things, but to think he didn't give a damn would come from ignorance based on lack of content.