Grinding is fine when there is a logical means to doing it such as high drop rates of that particular weapon in Strike playlists so you run Strikes for a few days until you get it. But when your dealing with Destiny's terrible RNG that will give you the same auto rifle 10 times straight rather than a new roll on the pulse rifle your after you shouldn't have to play the game for a year just to get the perks you want on a gun.