They tried the whole every 3 month new content thing. It didnt work and alot of people bitched about how those dlcs felt rushed and were all buggy. Bungie themselves said the rate at which they were turning iut content in year one was an unrealistic schedule to keep. The more simple fix is to simply release dlc that has substance. One you dont beat in the first week and spend hours grinding in for no reason. Bungie tried that with the exotic quests and stuff in year 2 but again everyone bitched.