The whole point of the movie was to instill a feeling of dread and misery. It's not a patriotic movie at all. It's about the loss of that young man's innocence and the horrors of war and how it ruins man.
War is hell. Anyone who thinks it's cool or awesome clearly hasn't experienced it. For a while after I got back from Iraq, I tried to avoid violent movies and war movies. I already relive that shit daily, I didn't need a reminder. After trying for years, I've found that there's violence in everything. It's nearly impossible to not watch violent movies. Even our comedies have people die, they just don't show the gore. So I gave up.
Humans are violent creatures. War is hell.