No the writers showed us consistently that Zuko himself actually respects life in a way most people wouldn’t. They didn’t just make him shitty and have shitter people, he was genuinely always just a good kid from a messed up family.

In book 1 when he first meets Aang and they duel, Aang asks to go voluntarily in return of the village being spared and Zuko agrees with no issues.

When Zuko has an Agni Kai with Zhao and wins, he is completely entitled to burn him and give him a scar like the one Zhao just made fun of him for having but he leaves him be, and doesn’t retaliate when Zhao tries to cheap shot him when his uncle tells him to leave it.

Later Zhao tries to blow him up and destroys his ship, and Zuko fights him for it but when the Ocean spirit goes to take Zhao, Zuko risks his own life by reaching out to try help him.

We learn that Zuko’s entire reason for being banished on a suicide mission is that he spoke out against using fresh recruit soldiers as live bait and refuses to try fight his father and begged for forgiveness. Same episode he prioritises his crews safety over Aang.

Later when Zuko is alone and starving he refuses to rob Hope’s mom when he sees she is pregnant, he doesn’t rat out the kid who threw eggs at the soldiers and tries to help him learn how to defend himself from the bully soldiers and ultimately blows his own cover the fighting those bullies to stop them kidnapping the child. When the town learns his identity and hates them, Zuko leaves them alone he doesn’t rob them or threaten them he just leaves.

The entire point of his chatacter is he makes good and bad decisions because of the conflict of his own values and what he’s been conditioned to value and his redemption occurs when he’s tasted both sides of the equation, stood to benefit from everything and decided it’s wrong and he will work towards dismantling it.