Because Destiny has become very boring, has a bunch of connection issues, lackluster DLC's and has barely any story. Right now a lot of players are playing Destiny simply to grind for new weapons and event gear such as in the IB. I'm certain that if Bungie is again overhyping this new DLC and it ends up being just as lackluster as the previous DLC's a lot of people will leave Destiny and I'm one of those.