Another thing that will keep a kid/person out of the military: Tattoos.
I took a 21 year old kid to a Navy recruiter. He asked about tattoos because that would be a disqualifier.
I started reading up on that and found that the military figured out that some people coming in with tats were gang members. They were continuing their gang activity while on active duty, then after getting out, taking their combat training back to the hood.
I know someone who served in the Army who had a couple tattoos on his arm before joining. He was told that some tattoos were allowed but could not be visible while wearing a uniform. He had also had a mild run in with the law. He served in Iraq and was injured by an IED, completed his service honorably and is a good husband and father to our daughter and grandchildren.