It’s not the hate. It just didn’t age well. Cameron also really screwed up waiting 10+ years to make sequels. No one really wants Avatar any more and now four more movies are coming which many don’t want or care about. And also Avatar has had its day as top dog. It’s time to to stand aside.
I'm always surprised by Cameron's success at the box office. ALL OF HIS movies are corny. But they are fun and they always deliver. I think the only movie of his where I didn't have several eye roll moments was The Abyss. But overall I enjoy them and I am not going to poopoo on the sequels until they actually come out.