Because a lot of people do have this weird idea that she hates him because he’s Fire Nation, and that she’s accusing him of shit he didn’t do, and so on. And they also have this idea a lot of the time that she somehow knows what we, the audience, know about Zuko and deliberately rejects it.
Neither of these things is remotely true. She hates Zuko because he spent series one trying to hunt down and take to his probable death, or at the very least imprisonment, her twelve year old friend. The friend who is determined to stop a war destroying the world. Because… he is in favour… of the Fire Nation winning that war.
And in the process, he does shit like LIGHT A VILLAGE ON FIRE. And ties her up and threatens her. And threatens her family. And also, when she gives him a shot anyway, he attacks them. And this directly leads to Aang dying. Oh, and then they conquer a city, implicitly dooming the entire Earth Kingdom! And furthering the agenda of the nation that started that war which is, you know, destroying the world.
The war, by the way, which killed her mother. Oh, Zuko didn’t do it personally, but if he’s in favour of the Fire Nation doing things like invading the other nations, how is she supposed to take that?
We like (or in my case, adore to a frankly disturbing extent) Zuko as a character despite all this because we have context. We see a lot of Zuko over the three series: Zuko with his uncle, Zuko on his own, Zuko with his family, Zuko’s inner conflicts. We see a lot that shows how he was the product of an abusive environment and so on, and we see that he wants to make things right. Katara? Doesn’t really see any of this. The one time she does, he makes it seem like it was a trick to make her let her guard down. All she sees is Zuko being a shitty person and attacking a twelve year old boy and so on. Why the hell would she share our sympathy?
Katara’s distrustful nature towards him is an attempt to make it clear that you don’t get handed forgiveness, you earn it. That’s the entire point of Zuko’s joining the gang when and where he does. They’ve said as much. It’s why series two ended the way it did, and why he spends so much of series three conflicted. It shows that actions have consequences, and if those consequences are ‘act violent and hateful towards people and they’ll hate you for a while even if you stop!’, I don’t see why that’s anything but logical.
okay rant over i just… really love that katara didn’t forgive him for a while, it’s great storytelling and i don’t see why people wish she’d done something far more boring and ‘nicer’.
It was so much more interesting that Katara didn’t immediately forgive him and was legit angry. It was also just a neat reversal, because it seemed like everyone expected Katara to immediately forgive him, and Sokka to be angry, but it was pretty much the exact opposite, which I love.