Well, body piercing is a "Look at me!" statement, don't you agree? Attention deficits often spring from low self esteem. Although there are many reasons to get these kind of things done, sometimes people add to their bodies because they're not happy with them. They want to be special. (And end up being just as "special" as everyone else, in most cases).
And from personal experience, it seems that the more body piercings and tattoos someone has, the uglier they started out. I mean, some of these ones who go overboard with it look like they've fallen off the ugly tree onto a stack of sharp metal things. ;-)
Well, that's probably not true for all body piercists/tattooists. It's just a personal observation. :-D