I would say that, yes, piercing is a form of self mutilation. However, the craziness of that can only be based on one's opinion.
My point basically was because we cannot prove any sort of objective morality in all cases, then those cases that are brought into moral question, that do no directly affect others, should be left up to the individual conscience.
I never said I was going to take away your right to pierce your tongue. I said that it is crazy [in a concrete moral sense] to mutilate yourself. I don't go in for subjectiveness. :)