You seem to think that Korra getting her bending back would be treated the same as Aang learning how to bend for the first time. They're completely different situations and could have very unique stories. In Aang's case, he was a bender who just didn't know how to bend all the elements yet. In Korra's case, it would be a quest to regain her powers, not by traveling to different nations and being taught by masters, but by reversing whatever Amon did to her.
Now, I'm not even saying that I would have preferred that over what we got; it's just another way things could have gone. Hell, it didn't even need to last the whole second season. It could have been dealt with in the first couple episodes with Korra accessing her spiritual side.