I get what you're saying and your arguments are well stated, but remember, a tattoo -like a T-shirt or a bumper sticker, except in a much more permanent, personal way- are decidedly external emblazonings of the symbols of your feelings, experiences, tastes, aspects of your personal life, etc. That they are external and and are, in fact, sometimes much easier for other people to see than for you to see yourself, (except maybe in the mirror) begs a dependency on the recognition by others -oftentimes strangers- of those symbols.
I have no doubt that many people get tattoos for very significant, personal reasons and that many people with tattoos find generic flash art insulting and disgusting. I am in no way contesting the notion of unique, personal relevance in many people's tattoos. All I'm saying is that it is a little hard to buy the "well it's my tattoo so fuck off and mind your own business" aspect when, as just stated, the basic foundational definition of a tattoo is that it is an image (to be seen) and that although personal in nature, it is external (on the outside of the person)...
My girlfriend has a huge blue panther, or a puma or some shit, tattooed across the side of her scalp. She got it when she was 18 and it means something to her (I guess) and it used to be very visible because she shaved her head a lot. Even though she is old now (early 30s, which is old for a girl), whenever she shaves her head for a cancer benefit, there it is again...a big-ass blue cat, right on her head. She has never implied regret for getting it done (she has many others as well) but she always expresses annoyance whenever some moron accosts her and is like, "dayam, didn't that HURT?..."
She is always polite and patient when she answers them "yes," but then when she bitches to me personally about it, my answer is always the same:
"Well, you did get a fucking blue cat tattooed on your fucking head. Deal with it."