People may argue that tattooing their entire body is artwork but I would suggest that they probably don't love their body in the first place to want to radically change it like such i.e. tattoo from collarbone on downwards and every square inch.
You have to wonder: Is it really about art, or are people covering up because they have body acceptance issues. I think the latter is very plausible for many heavily tattooed.
Self-acceptance of body is a real struggle for so many men and women.