There's a long and twisted history behind Marines being the way they are, and this film chronicles some additional twists that will feed into the lore going forward.
Instead of studying existentialism in college under the tutelage of hot professors (yes, Camus is a fine place to start), Swofford elects to take it straight from the horse's mouth. He works all the way up to nausea (ala Sartre) and really deserves some kind of degree in the end (he's a good writer). These guys should be making films, not just watching them.
The sense of wasted talent, watching one's youth go by in a desert (a teenage wasteland on steroids), understandably makes 'em psycho. The dead end job once they get home doesn't really make up for the sense of loss (dread, despair etc.).
The price of oil is really very high. We don't just pay at the pump.
Related post: A Catholic Economy (Nov 10, 2004)