First and foremost, Gjallarhorn is currently the rarest exotic in the game... It has only been sold by Xur once, and that one time only a few people had enough strange coins to buy it because it was sold the first week the game came out. Secondly, you probably don't even have the weapon. Gjallarhorn is the only exotic in the game that actually feels like an exotic. It's a -blam!-ing exotic... They're not going to take wolfpack rounds away from it because that's the weapons special ability. Changing the RoF of the weapon to shoot only 2-3 rockets every 20 seconds wouldn't do anything considering the weapons fire rate is already slow. And you're getting mad that you get kicked from raid groupd because you don't have Gjallarhorn, the solution is to find better friends or switch your console.