Why try to talk a mature, intelligent, stranger out of an action that does no harm to anyone, in fact only affects themselves?

Just curious, here, folks. On so many tattoo threads, there is usually at least one (often many) who completely misses the point of the Q and tries to talk the OP out of getting inked.
I’m not talking about young kids, but adults who are asking advice about getting their first. Not asking if they should. These people are old enough and rational enough to understand the possible ramifications of such an action, why question that?