Ok, very well made points, but please don't be offended if I disagree with them, that is part of the fun
And I hope however passionate that all take this in good fun, because it really is just about discussing and expressing view points.
Again, if Wall-E is not valid just based on conservation, then this also goes for Avatar and we have to take all aspects of it into consideration. Is it nessisary that Wall-E take place on Earth for most of the movie? Part of Wall-E does take place on the earth. The reason they are in space is they did not take care of the earth, which caused the natural environment and animals to suffer. This is the same idea of Avatar only it is preventative rather than after the fact. The skyscrapers of trash is the result of lack of conservation, so are you saying preventing it is a more fitting theme than acknowleging the results? The reason we believe in conservation in the first place is because we know what the results are and have seen them.
So are we really going to say that the validity of using a movie property in AK should be determined by the amount of time a movie spends in a simulated natural environment? And in fact both movies contain space flight and robotic technology, regardless of the screen time each receives. So can we have a themed land with a beautiful 'natural' environment and ignore that it is a land not found on this earth (thematically speaking of course). That it takes space flight to get there? Again, I just don't see how you go from Asia and Africa to Pandora. While we are at it, let's bring back Alien Encounter and make a alien petting zoo based on Flight of the Navigator (points to whoever knows what that is) since absolutely any animals are fair game regardless of the means in which their existence is determined.
How do the natural environements of Earth fit with an alien world? Just because it looks simular? You know, some people believe that Mars once supported life. Should we create a land about what the Martian landscape and animals would have been like? That would be about the same difference as Avatar. As neat as that sounds to me, I don't believe that it would fit thematically.