This is where we disagree. Also let me clarify, I'm a MASSIVE Potterhead. I've read each book at least 11 times (the last book 14) and have read each of JK Rowlings posts on Pottermore, so it's not like I'm biased toward Avatar. I think Avatar was a stunning movie, with very original storytelling (I don't consider themes part of a story), what I simply don't understand is why the land is being discarded as overpriced, unimportant, and weak, compared to a land half its size. The IP, at this point in time, is no doubt far weaker than Potter, but why should that mean that the two can't aggressively compete, not everything revolves around IP. Given that domestic ticket sales for Deathly Hallows Part 2 were $381 million, I think a lot of people overestimate the Potter brand, that compares to $760 million for Avatar, even Toy Story 3 did better with $415 million.
IMO, it's all about the delivery, the IP matters little.