It’s canonically important that he’s permanently and severely disfigured. I feel like they’re trying to go for that dark brooding thing teenage girls go nuts for (I sure as hell did) but don’t realize how important the severe injury / disability is to the exact story arc that made him catnip to teenage girls. And they’re honestly wildly overestimating how much that affects his “attractiveness”; like I said, it certainly didn’t matter to my stupidly horny tween self. It really reflects how shallow these people are. And honestly part of the reason I don’t care about that kind of thing as an adult might even be attributable to watching atla at that age, which is a great example of why that representation matters so much.
Also tbh the way he the injury looks in the original animation, I’m surprised if he can even see more than maaaybe vague dark vs light shapes out of the damaged eye, meaning he’s also disabled. I’ve had partial blindness in one eye since before I can remember and it can make sports that require depth perception difficult. The fact that he got the injury as a teenager / young adult would be even more disabling because he wouldn’t have the neuroplasticity of a toddler / infant to help him adapt like I did. Yet he still competently engages in ranged combat on the regular!
TLDR network / tv show executives are cowards and don’t actually understand what real people who don’t essentially live in the hunger games capital city actually find attractive.
I didn’t think about it until reading your post, but I think that’s why I related to Zuko even more during a rewatch as an adult after getting an eye injury in highschool.
TV/Movie rule: Only bad guys can have ugly features/disfigurements. Good guys can have scars, but only the cool kind. People might get confused if an ugly person was supposed to be a good guy.
It often goes the other way too. If you see an otherwise attractive character with an unsightly mole or other blemish, they’re probably a bad guy and will turn on the good guy.
And they do some dramatic reveal as if the scar was more scary and serious than it actually looks like lol.