For all that Lone Ranger was a mess in some ways, it was also well-structured in other ways.
Jonah Hex is just flat-out a mess, the kind of film that might find an afterlife as a midnight movie because it's such a mess. But I want to stress that might--because usually midnight/cult movies aren't just messes, but fun messes, and Jonah Hex isn't a lot of fun.
Honestly, Josh Brolin is OK as Jonah Hex, though that face wound turns his Southern drawl into something unbearable: an attempt to seem gritty and cool. Megan Fox and John Malkovich are both wooden, but not in a fun bad way. Honestly, the only one who looks like he's having any fun is Michael Fassbender as this psychopathic, Maori-style tattooed, bowler-hat-wearing Irishman. Maybe because there's no depth to that character and just a collection of traits that Fassbender can push.
There's a fine story buried here, with ex-Confederate loner Hex learning to care about the country again (or something) when faced with the evil unreconstructed Confederate played by Malkovich, who is seeking a doomsday weapon.
But so much of the story seems organized around what a 12-year old would consider cool, without any consideration of drama or reality. For instance, Hex starts out anti-social, as we'd expect of the anti-hero to hero journey; only his anti position is almost parodic without being funny. When he comes to collect a bounty and gets double-crossed, he doesn't just kill the double-crossing sheriff, but destroys the whole town. Naturally, he's riding his horse as the town explodes behind him.
For another example, Hex tracks down someone from his old life who now runs an underground fight ring. So naturally, we see this fight between a giant guy and a snake guy. Is that a metaphor for the fight within Hex? Is it important to the plot? Is there any connection at all? No, they just wanted to show us a fight between two weird guys. (I'm guessing 300 was an influence here.)
For another, final example, so many of the fight scenes that actually involve Hex are scored with over-the-top heavy metal. It's ... odd. I think it's reaching for something fun and awesome, but it comes off as trying too hard and not getting there.
But let's take a basic lesson from this mess: every scene needs some dramatic tension and conflict. Man, this film is maybe 80 minutes or something and it fails that basic test? That's a mess.