Pretty much this. I'm speaking as a fan when I say that Black Hammer is very overpowered in PvE. It's perk, which only it has, makes it worthy of being an Exotic. It's the only weapon in the entire game in which a single person can infinitely stun bosses. Had the perk always been like this, sure it would be slightly less popular now, but it would still be very popular for PvE.