I just got around to seeing this, and I wanted to expand on my twitter post about how bad I thought this was.
The movie has a "ridiculous-by-design plot" (as the AV Club says): it rambles around, takes a while to get started, does not really build anywhere, ends somewhat at random. In theory this can work. But the kind of movie that that works for is one where something else is OVERWHELMINGLY good, usually comedy. I cannot come up perfect examples here, but we will do with these: Harold and Kumar just kind of rambles around, but it is really FUNNY so you don't care; I have never cared an ounce about the plot of an episode of Pushing Daisies, but the design of the show, the casting and the characters are so great, it is never bothered me.
You can also have a movie with no sympathetic characters, but again, you have to be really funny or have some other over the top stand out quality. The best episodes of It's Always Sunny in Philadelphia are funny enough that the fact that the protagonists are all monsters does not bother you in the least -- in fact it ads to the comedy. The characters in Burn were either completely unsympathetic, or they were sympathetic in the wrong way -- I felt sorry for them some of the time, and that made the jokes not work for me. Instead of laughing at their unrealistic monstrosity, I pitied them for their realistic dashed hopes.
Burn After Reading has BOTH a ridiculous by design plot AND no sympathetic characters (or sad characters), which means that the thing on the other side of the scale (performance, jokes, design, special effects, whatever) is going to need to be extra heavy as a counter-balance. And there was barely any counterbalance.
Moments were great: the CIA stuff with JK Simmons was wonderful and the last scene in the film was my favorite; John Malkovitch in a bathrobe and shorts with a hatchet was brilliant. Brad Pitt was really funny dancing in the car with the headphones or holding up his fist when he calls Malkovitch at home. But there were a lot of scenes that I think were supposed to be funny that I thought (and people I like disagree with me here) were not funny. Clooney's basement project -- there was something really sad about that, and about how he called his wife (who is leaving him) to tell her her present was complete. Francis McDormand is dumb, but we do not hate her, and when she goes on a date and is disappointed we feel bad for her; when a date goes well but it is with another man who is going to hurt her we again feel bad for her. She is stupid to be sure, but not undeserving of love (and someone does love her) -- this is not good if you are going for comedy to counterbalance your story. (For the record I do not like most Christopher Guest movies, where, again, stupid people are punished relentlessly: I seem to be the only one who feels so bad for these characters I cannot laugh at them). George Clooney freaking out - that was supposed to be funny I think and I guess it was sort of funny, but it was not enough. There is a gag late in the movie -- I think it is supposed to be a gag but it fell so flat I could not tell -- about what Tilda Swinton's job turns out to be. I would love to have seen more scenes like Malkovitch punching Pitt in the car, but when the violence hit again it hit characters who got hurt I did not want to see be hurt. I wanted to see it get out of control like an Acme Cartoon, as stakes kept rising in a Malkovitch Pitt/McDormand battle, where each became steadily more monstrous and thus more deserving of violence, but instead it fizzled with hurt people hurting each other. I wanted a movie that got started fast and kept going, but the first act was spent establishing main characters in the status quo -- a fine idea in a movie where we are supposed to get attached to them, but not a great idea if you characters are all unlikable. There are long stretches without comedy at all -- so maybe comedy is not the thing that is supposed to counter balance the silly plot and the bad characters. But I cannot think of what should be the counterbalance, and I believe this movie needs one. It is like being at a party full of people you want to get away from.
My friend Tim said that the problem was that the movie had no main characters: it was like a group of quirky throwaway secondary characters from a bigger film. As a secondary character it is OK to just run on quirks (like Clooney's "maybe I can get a jog in"), but i felt like in this movie we were paradoxically spending too much time with these people (all minor characters consisting of quirks) and too little time with them (there were so many characters no one got much room to do anything and my favorite character just disappeared at the end of act 2, having not done nearly enough; Malkovitch did not do enough either and he is JOHN MALKOVITCH).
To paraphrase Seinfeld: if I want a rambling pointless story with filled with petty people being awful to one another, I have my life.