The military is desperate to recruit and retain individuals from a shrinking pool of candidates. They don't expect these people to stick around past a first tour but need them to fill certain tasks. Sadly, adding them to the group is going to chase out a lot of bright and capable people.
Another possibility is that they want to drive out dedicated USA-loving types and replace them with tattooed soy boys dykes and gangstas for the express purpose of making the military weak.