http://en.wikipedia.org/wiki/Inception#Ending - Nolan himself noted that "I choose to believe that Cobb gets back to his kids, because I have young kids. People who have kids definitely read it differently than those who don't". Good enough for me.
You're still right he meant to leave it up to the viewer, but it completely destroys the rest of the movie if everything is a dream. People want to play games with the rules the movie presented and hypothesize about the whether Mal is in the "level above"... but everything we think we know about the rules comes from that level. We learn about the multi-layer inception, the wife, the concept of limbo, everything in the movie, on that level. If it's all a dream, then there's no target to the obsession in the first place, no children, no wife, nothing.
Incidentally, note I'm sort of making a metapoint... if Nolan came out and said "Yes, it was all a dream" I would accept it. But it would still dramatically destroy the movie.
I'm also sort of hostile to the "all just a dream" idea, whereever it appears in fiction, because it's redundant. It's already just a dream, a movie, a book, a TV show, whatever. It's already not real. Saying that in the context of the not-real work of fiction the entire story was also not-real is silly. (Note the word "entire".) It started at the maximum level of not-realness from the very first word or frame. And it's a short trip from there to the Bergman/Braga incoherent style of ass-pull storytelling. (Or Tennant-era Doctor Who.)
You seemed to have skipped right over the first few sentences from the section you cited: "Nolan confirmed that the ambiguity was deliberate, saying "I've been asked the question more times than I've ever been asked any other question about any other film I've made... What's funny to me is that people really do expect me to answer it....I put that cut there at the end, imposing an ambiguity from outside the film."
:)
I agree that resolving the entire film as simply a dream would be a huge let down. If it were another film, would be content to stop there. For my money though, resolving that the ending puts Cobb firmly back into reality is also highly unsatisfactory. The more interesting (and I believe) intended result is force the viewer to question their own sense of reality. Haven't you ever had a dream that was so realistic that you were certain it was real - until you woke up? How do know for sure that we are not simply living a dream that we will one day wake up from?
There is a book by Stanislaw Lem that beautifully explores this sort of idea. In the story, there is mad scientist fellow that has a room full of electronic brains, each being slowly fed a life story via a series of slowly rotating magnetic drums. To the individual brains, the story that they are being told IS their life - they have no idea that they are simply boxes in some mad scientist's laboratory. The book goes onto suggest that our own lives may simply be programmed by a mad scientist who exists a level up from us.
I believe this it is this sort questioning of reality that Nolan is trying to impress upon the viewer. Reducing the whole thing to just a sci-fi film about a couple of dreamwalkers makes it seem frankly one-dimensional and uninteresting.
How would it dramatically destroy the movie? The term is existentialism. It may all be a dream, but that doesn't mean that you can't give your life (or the movie for that matter) its own meaning. I personally find this more liberating, than the idea that life is a game to played.
>It's already not real.
Dreams are real while we are in them.
Well... just off the top of my head, it would make the film insensible for a variety of reasons:
(1) It would make a mockery of what Nolan seems very clearly to intend as a positive ending. In the script he actually tells us he is centering the film on a simple, positive emotional message. So what is that message?
(2) It would create a glaring inconsistency with the symbolic landscape of the rest of the film. Case in point, the dream worlds are strongly associated with water symbolism, which even creeps into the real world when the dream world intrudes: it is a glass of water that sends Fischer to sleep on the plane, while Cobb's waking hallucination occurs while he is washing his face. And yet... unlike any other dream... there is no water at the end of the film. In fact, we have the exact opposite, since we are told the events take place in a garden on a cliff.
(3) An aside, but anytime you have people who are named after apostles frolicking in a garden with Dad, you should jump to asking yourself if there might be Christian imagery lurking there. So what's with all the biblical imagery, or the constant references to "leaps of faith"? Is it really accidental when characters blaspheme, or invoke religious imagery?
(4) the visuals of the children building castles on the beach would suddenly serve no purpose. There would also be no explanation for why Mal is supposed to be bad, when her name clearly suggests she is a malevolent character. Likewise, the names of James, Philippa and Ariadne would be meaningless. Ariadne's mythological role is helping Theseus out of a maze, so what is Cobb still doing stuck in one at the end?
(5) Cobb clearly develops as a person. Why does Nolan go to such pains to show this, and what does it matter if these changes accomplish nothing of significance? Which brings us back to point one, why doesn't Cobb just stay in limbo with his wife?
(6) This is a bit esoteric, but you'll get stuck arguing that Saito's palace is destroyed by water because Cobb was pushed into a bathtub rather than the opposite: that Nolan engineered the bathtub scene in order to find a way to destroy Saito's palace in a storm. This requires a violation of the principle of Occam's razor unless you're prepared to argue that there isn't really any water symbolism in the film, in which case you would be wrong. :)
You're still right he meant to leave it up to the viewer, but it completely destroys the rest of the movie if everything is a dream. People want to play games with the rules the movie presented and hypothesize about the whether Mal is in the "level above"... but everything we think we know about the rules comes from that level. We learn about the multi-layer inception, the wife, the concept of limbo, everything in the movie, on that level. If it's all a dream, then there's no target to the obsession in the first place, no children, no wife, nothing.
Incidentally, note I'm sort of making a metapoint... if Nolan came out and said "Yes, it was all a dream" I would accept it. But it would still dramatically destroy the movie.
I'm also sort of hostile to the "all just a dream" idea, whereever it appears in fiction, because it's redundant. It's already just a dream, a movie, a book, a TV show, whatever. It's already not real. Saying that in the context of the not-real work of fiction the entire story was also not-real is silly. (Note the word "entire".) It started at the maximum level of not-realness from the very first word or frame. And it's a short trip from there to the Bergman/Braga incoherent style of ass-pull storytelling. (Or Tennant-era Doctor Who.)