you don't think "best movie of all time" is too much of a hype? A batman movie can only be so good, it's about a guy in a cape. I don't know, but I didn't particularly feel a real emotional resonance with that movie, it was just entertaining for a few hours.
I'm not saying that every movie should be a reflection of society and our times and change the way we think or feel and define a generation, but I'd say that the best movie of the year, let alone all time, should be doing that.
Think about a movie like Apocalypse now and what that spoke to people. Darknight had a few ambiguous moral messages like you said and quality acting, but it was mostly just action and suspense.