I don't understand what would motivate someone to become what is basically a war tourist?
for someone who is deeply traumatized by the military, it can be easier to simply continue what they are used to. military provides rigid schedules and structure to daily life. you do what you're told. it is similar to how people have trouble adjusting to normal life after getting out of prison.
instead of worrying about taxes and rent and all the problems of civilian life, you need only think of what manual labor you are assigned to, where to stand, where to aim your gun. years of having someone else make decisions for you conditions one to have difficulty making their own decisions.