Sure - allow me to correct you.
I didn't join the Marines to become a grunt and be in an infantry unit. My goal in life then was to become a chef - I was in a culinary program in high school, working as a cook in a local restaurant, and my plan was to go into the Marines to be a cook for four years and then onto culinary college. Much to my surprise, I ended up in infantry as a TOW gunner.
Now that I think about it, for nearly half of my time in the Marines I was not in a combat MOS. For two years I was a combat instructor.
The vast majority of people in the military are not in combat positions. While this number varies from branch to branch, for the most part up to eighty percent of the military is support roles. The military isn't only people with guns - there is supply, cooks, fire fighters, motor transport, logistics, command, admin, police officers, doctors, nurses....
Here is a list of military occupations:
ASVAB and Army Jobs | Military.com
The person who signed up to be a "Carpentry and Masonry Specialist" most likely didn't think he would end up being killed in Niger.
Some people sign up to the military hoping to go to a foreign country to kill the enemy. But most people sign up to get gain a technical skill or get money to go to college.