It's probably been 15 yrs at least since I've seen the movie but my first reaction to your post was "Hmmm....I thought it was pretty good, did I miss something?" So to refresh my memory I went back to an Ebert review. Real good reviewers are are like real good lit professors, the best have studied films for years and can understand and explain the art way beyond what the average film goer even usually wants to know. I think Ebert was one of the best. Anyway his review was a thumbs up and in part said this;
"Yet you do not see as much actual violence as you think you do in this movie; it's more the tone, the attitude, and the breakneck pacing that gives you that impression. Stone is not making a geek show, with closeups of blood and guts. Like all good satirists, he knows that too much realism will weaken his effect. He lets you know he's making a comedy. There's an over-the-top exuberance to the intricate crosscut editing, by Hank Corwin and Brian Berdan, and to the hyperactive camera of Robert Richardson. Stylistically, the film is a cinematic bazaar, combining color and black and white, film and video, 35mm and Super 8, sitcom style and animated cartoons, fiction and newsreels. They're throwing stuff at the screen by the gleeful handfuls.
And look how this film blindsided the good citizens of the MPAA classification board. The review panel threatened the film with the dreaded NC-17 rating, and after five appeals and some cutting finally granted the R rating. But read their parental warning: "For extreme violence and graphic carnage, for shocking images, and for strong language and sexuality." They've got the fever! I could point to a dozen more violent recent films that have left the MPAA unstirred, but Stone has touched a nerve here, because his film isn't about violence, it's about how we respond to violence, and that truly is shocking."
I'm not saying his opinion makes yours wrong. A movie is subjectively judged, by "gut reaction" at first viewing like any other work of art. One thing I like about Stone's movies is they usually try to "say something" and are not just well hashed over formulaic entertainment. And Lewis, Harrelson, Jones, and Downey are four of my favorite actors. The movie worked for me, I think I might watch it again real soon.