Tattoo's that are thought over and not just picked out of a flash book usually do have a point.  Are you saying that monuments or tributes have no point?  It is excactly the same thing just in a smaller venue.  When it means something to you and it's not there to just look cool, then it probably has a point or meaning.  That tribal tattoo may have a meaning, but he said he wants one just like it,  I'm sure he is not looking into a meaning of any of it.