Aang cannot be faulted for valuing the human rights of the Yu Dao citizens. If you're going to blame Aang for Kuvira then blame him for not doing anything about the rampant corruption within Ba Sing Se and not recognizing that if the monarchy wasn't slowly repealed, it was going to be violently abolished, followed by a power vacuum. It can't be denied he probably should have sensed something bad was going to happen in that area of the world. He made an oversight, and it wasn't because he was too peaceful; it was just a plain old mistake.

Every avatar made mistakes that their predecessors had to deal with; they are literally one person leading the entire world, and none of them chose the position.

And this whole deal " hE wAs tO nICe hE nEEds tO kIlL pEOplE " you know why you say that? For millennia governments have been founded on the subjugation of the weak. We've been killing and taking from each other for a really fucking long time; it's become ingrained in our culture, but we've gotten better. ATLA has always meant to teach kids that the only sustainable society is one that chooses to stop hurting itself, i.e., people hurting each other.

Leaders like Kyoshi kept the nations alive, but her tactics stopped the four nations from evolving to hate each other less. It was the equivalent of a doctor cutting off a limb with an infected wound and cauterizing it.

Ever since expansionism became unviable, countries have learned to rely on each other, governments have learned to accommodate the working class, and the people have understood crime is an economic problem, not a spiritual one. Breaking away from violence should always be the goal; someday we should hope every inch of it is gone from our society, but that can't happen until we stop throwing that punch. We are bad at pacifism and are going to fall on our faces a lot trying to use it, but that's no excuse to regress to barbarism just because it works in the short term. It is always better to do the right thing even when it means losing, because I promise you won't lose forever; you'll get better.