Bagging on exclusiveness is illogical in itself, guns are fun to grind for because when you finally get rewarded with it you feel accomplished, proud, and exclusive. It's an exotic for gods sake, it should be EXOTIC. I don't agree with the premise of Xur in general because it breaks the meaning of exotic, but I believe he shouldn't sell the ghorn (if he did I wouldn't really care bc it's not that big of a deal but theoretically speaking) because it's one of those weapons you want to work for. Yeah some people haven't got it and that sucks but it's that carrot that keeps people going, as for being OP in PvE I believe that shortening it with everyone having it would suck the fun out of it. The funniest part of raids and strikes is when people ask who has the ghorn and 1-2 people pull it out instead of everyone, makes it more about tactics rather than power and I like that idea. If everyone had ghorn in a raid team then crota would be more of a joke and wouldn't take much tactical skill. This is all coming from a guy who doesn't have the ghorn btw. Check my grimoire.