Let me tell you why everyone thinks it's "great." The entire advertising hype machine surrounding the movie was about how "smart and complex" it was, how you had to be intelligent to understand anything that was going on.
After a few weeks of nothing but non-stop advertisements conditioning people to think the movie was some ingenious riddle, people walk into the theater and watch some mediocre thriller with a "omg is it a dream?!1one" twist. It's not hard to follow. At all.
Anyways, simpletons come out of the movie thinking "omg I gots teh plotz I am a genious!1one!1" Then hyping the movie becomes a matter of proving to everyone how smart you are, because EVERYONE thinks they are of above average intelligence and self-validation appeals to all.
People who claim they didn't like the movie are then easily dismissed with lulzy bullshit like "You, like, just didn't get it, man." or "You have to be a deep thinker / smart to understand it."
It's a good case of self-gratification. It's funny that the movie is universally loved when there are movies that are 100x better and more "intelligent" that are torn apart. Like Vanilla Sky. Inception is a good movie, don't get me wrong, but it's just "decent thriller" and it's not some "omg amazing smart person movie."
There is your David thread of June 2nd.