I think if anything Nolan wanted the ending to be ambiguous. It's funny, T'Baio
, that you argue against the ending shot since after I saw Inception
with some of my friends for a second time one of them argued how "cheap" not having the dradel fall really was and thought it weakened the film. She said that instead of discussing or thinking about the type of impact the film had on you, instead you're thinking about whether or not Cobb was dreaming. She didn't think that ending shot added anything to the film and even suggested it took away.
While I perfectly see yours and her point, I think I might have to disagree. I think it all boils down to your preference over how a film should end. Some people like definitive endings where everything or most of the things are either mapped out or resolved. People like resolution. However, there are some, like myself, who enjoy the ambiguous nature of open endings. Allowing the audience to determine which one was the true ending, and then having limitless discussions over why they think either one is the true ending. I mean, that's what we're doing right now, isn't it? So in that respect Nolan succeeded. And by discussing the ending, in a way we're discussing the merit of the film, since we need to get in-depth in order to figure it all out.
So I think the ending shot isn't cheap, but I guess it all boils down to preference. Either you're a fan of ambiguous endings or not. I may be over-simplifying it, but that's the way I see it.