A couple of years ago, I was standing inside a coffee shop, fiddling with the condiments in front of the main window. At a table outside, an unbelievably gorgeous young woman, looking like Nicole Kidman's more voluptuous younger sister, was showing a middle aged man in a suit a large album of tasteful fashion photos of herself. Apparently, she was a professional model and the man was some kind of agent or editor.
"Yes, a beautiful girl."
"And she's got a lot of tattoos!" he exclaimed, with a wild look of excitement in his bloodshot eyes.
That struck me as, by far, the least of her charms. On further reflection, though, I assume that her tattoos signaled to him that, while you might think she wouldn't be interested in any fellow below the movie producer / hedge fund manager level, she was actually a really bad decision-maker. So, he had a chance!
You might think that a girl who wants to send that message to hungover guys who look like washed-up ex-motocross riders might find a less permanent way to advertise this fact (such as dress, make-up, or hairstyle), just in case she ever changes her mind and wants to raise her standards. But, in our culture, we have such a commitment to authenticity that countless women feel that it would be downright immoral to advertise that they are bad decisionmakers only part time. Hence, tattoos.