While I agree the sentiment about Star Wars. The flip side can be said about Marvel, which I think was the biggest push for the FOX acquisition. Marvel has thrived under DIsney.
Another +1 for a dream is that when Mal shoots Ariadne. Cobb rushes to spin the top and is interrupted by Saito. Meaning From that early on, we don't technically know if he left the dream so the rest of the movie may have been a dream.
Also Michael Caine isn't best source for Inception material. He claimed because he saw the top drop(while filming the scene) it means it was reality. Ignoring the fact that the top dropping is cut, leaving the answer ambiguous.
Despite that I think it was all reality. Although I like how it leaves each person to interpret it how they wish.