Korras issues were all about worldbuilding for me.
Imagine making TLA, debatably the cartoon with the absolute richest setting ever, and then throwing it out the window for steampunk shit.
Not only that, but by making Korra the next Avatar after aang, they effectively locked themselves out of ever using the original setting again since it's outdated just a few tests down the line, and you can't go backwards without jumping 100 years.
Fuck Korra and fuck the way it locked TLAs worldbuilding in a box