You'd think it was that easy but there's two parts to it from what I see. Look at no time to explain. It was a legendary and now an exotic. Why? Because you can't have OP legendarys in the game anymore. Look how much work it took them just to reintroduce this gun into the game.It's a separate story line which doesn't necessarily parallel ttk. The second part is that even upping the difficulty of the previous raids would still make these guns too easy to obtain. The mechanics to these raids are second nature for most now. You would have exotic level guns in 30 minutes or less that are better than the current legendary and exotics in y2. Bungie isn't going to let that fly anymore. Their goal is to make you grind out for these by consuming your time and effort.. effectively you're earning it. So they need to build out more quests for these "time locked" guns to keep the content drip in place.