Look, I'm not saying the film's well documented flaws aren't there. And for many an intelligent viewer, those legitmiate flaws are enough to wreck the film. But for those of us who are turned on by a certain brand of rural dialgoue and/or by films that set a heavy mood of honest reflection and stay in that mood from start to finish, All The Pretty Horses is rare enough and good enough to swallow up any surface objections to plot holes, structure trouble, etc.
The dialogue is great without wearing its greatness on its shoulder. Billy Bob is a great pairing with the novelist McCarthy because they both understand how to keep dialogue subdued and unassuming while fleshing out some of the most haunting themes.
The lines have meter. They're often poetic without going over the line (I'm lookin' at you, Terrence Malick). Listen to the cadence in these lines from the opening scene, especially the middle line:
"Down in Mexico, they got ranches so big, you can't ride from one end to the other in a week. It ain't all fenced in and sold off and played out. Not down there."
Or consider the poetic repetition in these two lines:
(in response to "I ain't the same as I was.")
"You are inside. Inside you are."
"Don't cry, Alejandra. Alejandra, don't cry."
And as artsy as that might look on the page, the lines are delivered very naturally by Damon, as naturally as would roll off the tongue in real conversation.
And it goes on and on, the poetic, but unassuming dialogue. It's masterfully written and executed in this respect. The same goes for the down-home quality of the dialgue. Without drifting into pure fable, or over-precious Southern Culture, exchanges like "Where'd you get a gun like that?" "At the gettin' place." haunt rather than just amuse. All this is accomplished by restraint in the writing and in the acting.
As for the mood, I bought the dreamlike qualities of the movie hook, line, and sinker, though I can sense how some would roll their eyes. The bizarre prison scene where the prisoner is singing, the mocking Spanish dance the Mexican ranch hand does while Cole is on the phone with Alejandra, etc - those touches of surrealism were right up my alley. They're all the more effective that they are sparse in the film.
As for the common complaint that the love affair is empty, I can go along up to a point. It's based on instant chemistry, and the pair treat the relationship carelessly. But those two facts go together: an animalistic love affair is going to be treated foolishly. That doesn't make the love completely shallow. Sometimes that's how we fall in love and it can be irresistible. I don't think falling for Penelope Cruz across a crowded room or ranch is much of a stretch. My lady friends tell me the same is true for Matt Damon. It's not the noblest kind of love, but it's plenty powerful. Cole's and Alejandra's nobler impulses do take over at natural points and foil the affair. That's as it should be, too.