Actually I think this is a good thing. It is a third world right of passage to have various tattoos. In an educated civilized society tattoos are not all that attractive. Yes I have seen some very nice ink work but over the years tattoos age (as do the people having them). Even with out that the truth is that the folks who insist on getting lots of visible tats are trying to prove how anti establishment they are. There behavior at best is marginal. their work history sketchy and their bill paying ability limited. More often than not they have trouble with the law as well as trouble with drugs and alcohol.
For those of you with tats good for you. I am citing my own experience.
The armed forces don’t need these kinds of folks.
It's tats above the neck and past the wrists - which, though my knowledge is *very* old, used to be illegal to perform in at least several states. (Tattoos on the genitalia are also illegal, but that's not germaine to this particular discussion. :-) )
IMO, and I'm just talking here, I'd guess that mostly it's to disqualify people with gang tattoos. That's just a shot in the dark, but I don't think it's a stretch.