Because they are hard to use, my brother and I use a shotgun PvE constantly. Sure they can't do anything against a strike boss unless you are a defender Titan, but against anything else you will find they do a ton of damage. I find the 2x damage boost unwarranted as the people who were always using them like us thought they were already awesome. So a win win for us, PvE Invective and Universal Remote is a beautiful thing with the right set up. Oh yeah if these are really double damage swordbreaker will 2 hit minotaurs. Can't wait til the patch is released. edit: Plus the HoW exotic is a shotgun