I rarely use them because I think they are cheap. Every match in crucible there's at leaset one guy with a shotty and nothing else. When you run into a room and kill one guy, that one guy's teammates are all gonna shoot you so while you die with 100 points they get 100 points plus the two 50 points for the assists. Additionally if you use nothing but shotguns in the crucible and you find yourself in a medium to long range situation what are you gonna do with a shotgun? Nothing you simply don't have enough range. To many people rely on shotguns that is bordering on insanity.