what's the "message" then?
you have given the answer earlier by yourself. on one side you seem to give credit to cameron and on the other side you are blinded by the hate.
a weak storyline is even better for cameron. it means he still has some potential to create a better storyline in avatar 2 on his already exisiting new world. knowing avatar will make more than $2 billion imagine how it will look like for avatar 2. it will be higher for sure judging by the law of the box office after people saw a good movie with high rates.
also smart one by cameron to get % from the success of the movie and not getting paid a fixed salary. he must have known about the success and so he earned more money.
If someone creates quality art whether they make 1 dollar or 1 billion dollar in profits it shouldn't matter one way or another.
you have a van gogh or picasso to sell for 1 dollar? i will take it.