This is no longer all that true. A lot of "trouble" one finds, even as a teenager, can keep you out of the military. You might be able to get a special waiver. After all, they want to only enlist upstanding citizens into the military. The days of offering young offenders military service rather than legal trouble is basically over.

It does still remain on of the US's largest jobs programs, though I'm not sure this is the goal of the military. It does make reducing military spending rather tricky since so many livelihoods depend on it.