My problem just is that Korra said she deserved almost getting killed by Zaheer so she could learn to be compassionate. She didn't need to learn that. She tried talking to every single villain, maybe not for long but she did try. However her sparing Kuvira is treated as something game changing for Korra. I don't think it was, she just never had the chance to spare any of the others herself.
Because lets remember that Korra didn't kill Amon, she didn't even capture him. She tried to save Unalaq, but wasn't able to, and Zaheer was just imprisoned, but not by her. So to me the lesson she learned was completely misplaced. Instead i think she should have learned that the world doesn't need her, and that's ok. Or that sometimes bad things happen and that is not her fault.
Allthough i am also happy she didn't kill Kuvira, and that for once she got to bring in the villain herself, even if the talk they had felt very forced. However i think they treated the problems facing them now that Kuvira isn't in charge pretty poorly by having Korra just leave for some time. And yeah the equalists disappeared very quickly for no reason too.
Also just to clarify, i don't hate Korra or LoK or anything like that. I'm just frustrated with how much potential it had and the promises i felt it gave, but failed to live up to.