Advice from the old lady:
I agree with
@AureliusMaximus about "it depends". And I have an interesting perspective in that I myself do not have ink, my fiance (a guy who looks like a rock star and has been in the music industry) has no tatoos either, and I have clearly informed my kids that there will be no tattoos (or kooky hair color) while residing under my roof....
But my 18 year old daughter, who is in a LTR for almost 2 years with a musician she went to high school with, is very creative and artsy and plans to become a tatoo artist specializing in botanicals. He's also very creative and artsy. And she was a virgin long into her LTR (she might still be, I'm not naive but I don't know), and they might end up as life partners/marrieds. She does not have any tatoos yet, but has shown me the one she plans to get (she has drawn it herself) and it is an old fashioned looking botanical type illustration she plans to put along the outside of her lower leg once she moves out this summer.
So I'd say she does not meet the standard "red flag" list you guys are talking about. And it makes sense for her to have some ink because being a tatoo artist with no ink would be rather weird. Her rationale is actually pretty smart. Tatoo artists can make great money as an artist, and her desire is "to help people express their creativity through body art".
She's extremely responsible and respectful and has a much more thought out game plan for her life than lots of people her age.
And I know a basist who plays in several bands who has a cool live in gf, she has lots of ink and pink/purple hair, but so does he. So they match as an artsy couple. They are utterly smitten with each other and just bought a house together. Ya. It depends.