Oh It DID!
They had the right idea but LOK lacked certain qualities that made TLAB strong.
I could likely write a hole massive spew on where the creators jump off the tracks.
That's is the short version
I mentioned one, No singular villain.
The fire lord had character, the fire nation had purpose.
We where shown one side of them both at first but as the series progressed they pealed back the layers to expose the fire nation as a not all bad. Wile the fire lord turned out to be REALLY Evil.
Aang found a way of dealing with the fire lord with out killing him which was his biggest struggle. By the end theru Zuko, the fire nation is even redeemed.
Now compared that to the many many villains who are mostly a threat because they one way or another remove Korra's power or poison her...Her banking on all the people around her instead.
Like yanno who knew the avatar was so easily dealt with.
That was the biggest problem. Korra DIDN'T struggle.
Her powers where always dealt with removed of hindered, but her friends came in to pick up the slack.
Aang had Sokka Katara and Toph yah but they fought with him.
When Aang failed THEY failed too, (fall of ba sing sae, the failed Invasion) Both times thay worked together and picked each other back up and grew stronger.
What did we get with Korra, Lots and Lots of her self pity. Her friends picking up the slack.
She fails they keep right on going without her. She wins, its time to move onto the next bad guy...
Lets toss in a hole bunch of old TLAB characters and explore everyone who ISN'T the avatar.
A change of pace can be nice, but in LOK case it went right off the rails and crashed into a revive.
Which was sad because the show had so much potential.
I didn't even watch the end of the series, I heard it was aweful.