Actually, Bungie already "has it right" for what are THEIR goals. Which is to keep players in matches all the way to the end, rather than quitting and finding another match in an effort to maximize individual rewards at the expense of the group play experience. OTOH, if you have no ability to predict what you rewards will be for any given match...then there is no way (or incentive) to game the system in order to generate a particular result.