Haha, I wish they wouldn't. I don't care if it'd be considered 'milking the franchise', I'd 愛 to see もっと見る seasons, with the same characters. A prequel could be cool, but if they continue the franchise, I hope they continue with Aang and his crew
They ended it because before the first episodes the makers of Avatar: The Last Airbender had the whole story planed out, they knew exactly what was going to happen and they would only have that many episodes as plan, when the story came to the end so did the show. It had nothing to do with the ファン base.
its just like 本 あなた get so bumped up about the 次 chapter that at the end they leave あなた hagning but its not over cause the movie is the ast chapter and were all waiting for it to be writing.