Alright, so let me clear something up, first of all, Gjallarhorn has the same drop rate of any exotic. they aren't going to make it have a lower chance of dropping just because it is "the Gjallarhorn", second of all, the only reason so many people want it is because of the wolfpack rounds for Crota. as we all know Crota is the laggiest part of the game, so when you hit Crota, your rocket may not do damage do to lag, therefore the wolfpack rounds are compensating for that loss of damage. I think we just think its rare because when we get an exotic we don't have, we then have a lower chance of getting an exotic that we don't have.