One thought on why the comment came off badly is that while Avatar's universe does seem to have a great deal of racial fusions going on, Hollywood doesn't.
And an Asian (or any non-white) can tell you that Hollywood tends to slant things so that it's the strong, noble, white guy/girl who's given the good parts. While the rest of us get the sidekicks or the villains. So when an opportunity comes for Hollywood to make up for all the Western men playing Charlie Chan (with associated accents) and telling Barry Hughart that no one wants to watch a movie about a bunch a chinks*, I think it's understandable to be disappointed and even seriously pissed about the subject.
*This incident is hearsay for me, so I don't know for certain it happened.