Lt. Trull wrote:
I thought what worthington brought to the Na'vi what that he was a warrior...
he was a United States MARINE...
everything else was gravy.
That's my opinion as well. The Na'vi are so intertwined with the forest there is no growth among their society and people lived the same as far as they remember their generations then the sky people show up. There is no scarcity to force the people to strive for more as the forest provides for all their needs, even if a predator eats one or two of them every so often.
They are presented with avatars, scientist who are useless, they have no function. They have no skills to add to the society and their feet are to soft to even walk around. With Jake Sully they finally ran into someone with a purpose. Maybe stupid in the ways of the forest but at least a man with a purpose in life.