You are correct on almost everything, Ace of Spades is still fun though. Every other raid and PoE seemed to reward you with something worth grinding for, Found Verdict, Oversoul, Pradeth's Revenge and many others I can't spell. If a new guardian starts Destiny and would have 3 raids, PoE, ToO and Crucible to choose from, all with usefull rewards that can be used in todays game, they would have something to keep them occupied for a while. Also, if everyone is so afraid of Fatebringer, Bungie could make an even better gun to make use grind for to replace it.