You guys are trying to read ROTJ as a realistic adult film that makes a priority out of logic. It wasn't that. It was a kids' fairytale with a happily ever after ending that implied the conflict was over. I think you want ROTJ to be that realistic adult film, so you can't accept that it wasn't and thus won't let yourself see the message the fairytale ending gave. No offense, but I think you guys are over-fixating on logic because you are in denial about being fans of a kids' thing. I've seen this sort of attitude before, in fans of the original Doctor Who show, who tried to compensate for the fact that they were fans of a kids' show.
And it's irrelavant that the novelization can be considered EU. It was the most important companion to the film. They wouldn't have put in that "The empire was dead" unless that as Lucasfilm's view. The novelization was the thing that everybody read along with the film and it was spelling out what was seen on the screen. And yes that line was poetic, but I see nothing to imply that it didn't also mean what it said. Star Wars back then was the sort of thing that gave you what it said on the tin ("can" in Ameri-speak). It was straight up. If they said the empire was dead they meant the empire was dead.
I think zombie84 (the writer of The Secret History of Star Wars) says it well in his post on the subject:
zombie84 said:I agree--logically, the ROTJ ending makes no sense; yet emotionally, it was always quite obvious to me that the message conveyed was that the Empire was defeated, and good guys won. I mean you practically could have had
"And they lived happily ever after"
when the iris closes on the final shot. Thats the point--thats the message you get. They can't live happily ever after if ROTJ just amounts to a strategic victory, the message throughout the entire movie, emotionally, is that "this is the final battle--it gets decided tonight", which is why all the sacrifice and basically putting your eggs in one basket approach (ie send the entire Alliance in a last-ditch battle to destroy the death star).
Personally, i never considered that there was the Empire out there, and I never knew anyone that did either--the film says "the good guys won, the Empire is defeated." Certainly that is what Lucas was trying to convey, and I think it largely worked, even if it doesn't work in a real-life setting, but then Star Wars has always been full of logical holes like this. While we are contemplating why the Rebels are celebrating what is only a strategic victory, we might also be contemplating how they can be celebrating on a planet that should be having nuclear winter.
Back before Zahn's trilogy took a revisionist take and kept the empire going after ROTJ, the EU treated the empire as mostly over after ROTJ. The Marvel comics spelled out that the galaxy was free after ROTJ. On the set of ESB Lucas said that in the next film the empire would be finally defeated. When Lucas put in the celebrations at the end of ROTS the implication there that the empire was over was not part of his SE revisionism. He was just making clearer what he'd already implied in the original film. Maybe it was a reaction to the way the 90s EU took a revisionist take.
The line "the empire was dead. Long live the alliance" is a rather poorly thought out line too, considering you wouldn't need the Rebel Alliance to live long, since their purpose was served.
Not true. You might expect that after the empire fell the alliance would try to set up a new government (like in the EU). That's what that line is implying. The alliance that was rebels is the new power in the galaxy, replacing the empire -that's the implication. Notice they didn't say "Rebel alliance", just "alliance", as in they were no longer rebels. And if the line was poorly thought out, so was much in ROTJ, so why should the novelization be different from the film in that? But poorly thought out or not, it very clearly said that the empire was DEAD. And I see no reason to think that meant anything other than what it sounded like.