Why do you hate the great divide episode so much (might want to spoiler your answer)?
And I suspected this was the "problem" with korra. I think the reason TLA worked so well is because it appears they had a single story they wanted to tell. They had four seasons and a good amount of money to do it. Korra is them taking less fleshed out stories and ideas they've kind of made up on the fly and doing it in one season. Kind of similar to Animes, where the best ones are usually the ones where they have a single story they want to tell, they tell it and they're done. Things like Bleach where they have arcs practically never match up, and Korra would be closer to the the latter.
Uh.. Long Story short: Great Divide is so completely useless to ANYTHING else that it's practically a big lipped Alligator Moment. The Ember Isle Players mocks the episode, so you KNOW it's bad.
TLA had 3 Seasons, not 4, and Korra's aren't Bad per say, it's just the execution SUCKS hard at moments. Like, Season 2 has a really cool premise, and a really cool middle part, but the beginning and the end are two giant pieces of meh/subpar storytelling. Season 1 was actually pretty well paced and was on track to beat out TLA's season 1, but then we get what is becoming a staple of the Avatar Franchise: Deus Ex Machina Endings. Season 3 is able to really play off of what was good with season 2, as well as some interesting ramifications and ends strong for Season 4, though Season 4 so far has been resoundingly a meh on my end.
I guess my biggest issue is that each Villain we've had isn't a GOOD villain, if that makes any sense. For me, there's two completely opposite ways to make a good villain: The Maniac who cares for nothing but his own self ambition(R/B on the Colour Wheel, see the Joker, Ozai, Azula) and the tragic Villain, the one who is doing what he believes is right for the world but is confused/viewed as evil(R/W, see Ozymandias to a degree, V(Though his status as a villain is debated)). Korra somehow tries to fuse the two, which...doesn't really work. We get characters who START off being a R/W, being driven by their emotions and experiences to act, but by the time the season is ending they've basically turned into/been exposed as "MUHUHUHUHUHUHU. YOU'LL NEVER DEFEAT ME KORRA SAN, WITH MY NEW AND IMPROVED KAIJU BODY. I AM GREATER THEN YOU IN EVERYWAY, AND I SHALL WIN THIS BATTLE AND RULE THE WORLD". IDK, I just enjoy a good villain and Korra kind of goofs up.