Story telling is just the beginning. One element that made HALO work was the marines. You had NPCs on your side, they reacted to you, gave depth to the experience, and damnit, you wanted to keep them alive. No equivalent in Destiny. Tower has those bots, the Reef has troops, I wouldn't mind if the City had some 'regulars' or something. Hell, make us uber Guardians and put some NPC Guardians maybe, I don't know, but something along the lines of friendly NPCs fighting beside you. Something to give it the feel of HALO when the marines would see the Chief and act like God himself just showed up to help pull their butts outta the fire. That was GREAT for storytelling and immersion.