Blame S.A. AG Michael Atkinson. He's the one holding back an R-rating for video games.
He has a screwed up sense of reality and believes there should be no R-ratings for games in order to "protect adults".
He maintains this line despite most other AGs, to my understanding, having no problems with the idea of R-ratings for games. Even one of Atkinson's own sons thinks he's stupid for holding back R-ratings for games.