Obviously, the job is stressful all in itself. While I did not go to combat myself, I have lost friends, I've delivered flags to families of Marines who fell in combat, and have also just had a lot of beers with friends who could not cope with some of the actions that they had to endure in combat.
Secondly, management is certainly an issue like any other company. I won't go in lots of details here, but for half of my enlistment, I loved my leadership as they pushed me hard and helped me grow. They very clearly wanted to make me a better Marine and person. They were as close as family to me. They were very balanced. They knew when to be be hard, and when not to be. On the other hand, for the second half, It was the complete opposite and my time was miserable.
I experienced similar things in the private industry, only with much less physical labor. :)