@TheHappySpaceman
I think it’s because the creators seriously began to sue Aang. The Avatar being infallible really does begin with Aang. All of the other Avatars gave him the same advice concerning Ozai for example. Yangchen gives him the best advice, along the lines of
“It’s not about you or your needs. Being the Avatar is about doing what’s best for the world. So stop being a selfish little prick.”
He ignores all of them and is proven right in the end.
The rock of plot contrivance magically gives Aang full control of the Avatar state, so he doesn’t have make the decision of that or Katara. They felt he “deserved” to have her in the end.
On a separate not, I find it interesting that Katara’s character is essentially destroyed after she hooks up with Aang.
Hell even adult Aang is straight up modeled after Dimartino, by their own admission too!
SELF-INSERT
As for Korra, well she is written much like Aang in how the obstacles to her character growth are treated. She’s introduced as a powerful, aggressive warrior who has to navigate a time of peace, she’s not very spiritual so airbending is elusive to her, the looming conflict with the non-bender revolution is treated (at first) as this complex social issue about systemic oppression, a problem she can’t just punch her way out of.
The Non-bender thing is almost immediately made black and white because Amon and his Equalists are a bunch of violent psychopaths. Turns out it is a problem she can punch her way out of.
The airbending just sort of happens, I guess seeing Mako in trouble suddenly unlocked that?
When Korra gets her bending taken away, Aang (he is one with the
Deus, he has BECOME the
Deus) magically gives it all back and full control of the Avatar State and Energybending, in the same episode no less! She does no work whatsoever. She doesn’t have to change. The narrative changes for her.
That’s just the first book, but this pattern repeats.