After Crota the Ghorn will not be as demanded and you won't see it in raids as often. Look at VOG you really only see it used about 2 maybe 3 times during the whole raid as most people use icebreaker or something else. Also selling it doesn't mean the people using it are going to magically be better at the game. Someone who dies always in Crota for whatever reason is not going to not die because they have a Ghorn equipped, it will help them shoot a rocket at Crota but they still have to stay alive. I've watched many people with one think how good they were only to be the person that keeps the raid from success because they aren't very good or can't think outside the box during the fight and react to the changing situation.