I think it's too 'niche' of a setting, only a select few would want it that way. Also a lot of fantasy ballers are purists, any deviation from the norm would be considered sacreligious. I know some people who don't even want Flex positions because it's 'unpure'.
2009 Winner - 12 Man Yahoo PPR League "We will mock you" - MVP - Phillip Rivers
2009 Winner - 12 Man Yahoo PPR League "Do dirties" - MVP - Joe Flacco
2009 Runner-Up - 14 Man Yahoo PPR League "Posse 4 Life" - MVP - MJD