If you expect an orange and get an apple, you're automatically not happy, no matter how tasty the apple is. That's where a lot of criticism comes from.

I found Inception to be a masterpiece. Yes, there was a lot of explanation to do, but it never felt unnatural and was necessary for the mind-blowing climax. Unlike Memento or Mulholland Drive, everything made sense to me right away. And ending the movie with the spinning top was just a genius move, especially since it was so carefully placed right after the intentionally dream-like airport scene. Never has such a static scene held so much tension.