I have a feeling they dont have the time nor resources to fix the game as its current state. If they are going to make Lvl40 Vog and Crota, that will take as much time as they would make a whole new DLC. So they are juggling with a bit of things here, and a bit of things there. If they make the old content relevant, community will be shouting for new content in that time. If they make another DLC, Community will shout for making the old content relevant. It sucks that they cant keep up with the players demand.