In my mind this is very simple, if George does not finish his series, and you are a fan; would you continue to buy books from him, and by that I mean books in a new series. If you wouldn't, a simple question of why is in order. If you can't answer that question with anything besides "he didn't finish the first series, so why would I start a second one", then you have the answer right there. The author in question obviously failed to fulfill your expectations. And that's what this is all about, simply expectations. An author does have certain expectations from his fans, if he starts a series it is expected that he should finish it.