The real problem with this movie is that I believe it was actually supposed to be an over the top more cheesy fun movie like Good, Bad, and Weird or The Warrior's Way, but Hollywood got involved so we ended up with a disjointed (seriously the last movie that I rolled my eyes at so many scenes was Hurt Locker as things don't even make sense within the scene, let alone let you suspend disbelief) mess of social commentary as the focus. Compare it to those other two where they take cliches and tropes but add over the top characters and action that makes them fun.
The premise and even the setup would have been fine, even fun if they'd not tried to make it gritty and realistic. But its like they took Titanic and said "yeah but what if we put them on a train?" and dropped the love story and tried to up the action.
I cringe everytime I think about this movie for how ridiculously awful it is. Like the Gangs of New York esque scene where the train magically widens to about 10 times the size just so they can have that awful "I'm in the middle of the fight but I'm going to stare down and then just walk over to the main character" cliche or the scene where they try to shoot each other through the glass while the train rounds a bend.