I guess the issue is that they HAVEN'T done that. They have the same amount of loot and the mod system doesn't offer the level of complexity to offset the lack of replayability that static rolls have caused. And I think it would be difficult to even hope that bungie would overhaul the entire loot system at this point. So this is how it will be for quite some time. MAYBE 2-3 DLCs down the road after enough complaints they will try to remedy this.