Thinking more on this sentence from A.O. Scott's review:
The accomplishments of "Inception" are mainly technical, which is faint praise only if you insist on expecting something more from commercial entertainment. That audiences do -- and should -- expect more is partly, I suspect, what has inspired some of the feverish early notices hailing "Inception" as a masterpiece, just as the desire for a certifiably great superhero movie led to the wild overrating of "The Dark Knight."
I wonder how much of the movie's reception is influenced by the narrative around Christopher Nolan. He is, essentially, the guy who makes summer blockbusters for the high-minded. I get the sense that reviewers have a good deal of respect for Nolan's talent, but with the respect comes high expectations. The extent to which Nolan fulfills those expectations then becomes a subject of debate. The result is that while critics are certainly mainly reviewing the movie, they're also are, in part, reviewing each other.
It's likely that this is a common feature of criticism. I actually wouldn't know, having read so little of it in other art-forms.