So, in Halo Reach, there was "commendation farming" by starting a checkpoint, killing all the things, resetting. Bungie said it was completely legitimate to get your commendations that way since you were simply playing the game... Later on, there were folks who found out that disconnecting from the internet after completing daily challenges got you the rewards, but then allowed you to complete them again to get rewards repeatedly. This became a thing. The folks who directly manipulated their network (pulled their cords) were banned - the folks who farmed checkpoints were not. Soloing the raid? Not on the same level as dropping host (pulling cord/quitting app) to gain an advantage. One is ban-worthy and one is not. One is so very obviously wrong, and the other isn't. Cheesing the nightfall? Not on the same level as host resetting Crota. People attempting to justify it are placing themselves directly in the crosshairs of a potential ban. Bungie have done it before, and will likely do it again. Not worth the risk when it's easy enough to beat him the right way