Right? It's complicated. Your example raises another point I didn't think of while writing the post. Getting a tattoo (or even ritual scarification in a particular, significant pattern) also has the added complication that you are getting something of beauty or at least significance that you don't get with self-flagellation or cutting or the like, which also seems to change the intuitive moral valence of it. But you're right, cultural acceptability also makes a big difference - I grew up with a very strong anti-tattoo bias inherited from my parents, but having been in the Army, a lot of my best friends have extensive tattoos, so while I still haven't felt the desire to get one, I'm a lot more accepting of the idea than I was when I was younger.