If you don't agree with me, that's totally fine. We don't have to agree on everything. But I do disagree with you that it's being nitpicky, or not something that can be criticized. This is the way I see it...
In an adventure story with a "group" helping the hero, members of said group need to bring something to the group. This can be a skill, or even something like personality. But there needs to be something each member possesses, as this strengthens the group as a whole. ATLA did this really well.
My issue with Korra is that ultimately, outside of Asami providing money and vehicles, no one is really bringing something special or unique to the group. They are just filling in basic physical support. The side characters don't even really get enough time to ever really stand out on a personal level (since there is so many things going on each season).
Now, if characters aren't going to have a special skill, or contribute something to the group (that only they can), then I think there needs to be something else there that justifies why the group is together. Korra has mostly done this with "friendship". They became friends with Korra, and so they are sticking by her.
That's totally cool. But IMO they have not done a good job with the friendship element in this show either. I don't ever really feel like they've grown together as a group, or should even really care about one another, outside of casually being friends. Do you? Do you really think they've done a good job with this?