The Gjallarhorn and the Black Hammer, possibly the Icebreaker as well, were the only nerfs ever made because of PvE. But it's because the Horn and the Hammer were genuinely overpowered weapons. The majority of the PvP nerfs are the result of a bunch of dumbasses screaming at the top of their lungs until Bungie caves in.

I know ghally was. People were making it a requirement for fireteams and got pretty toxic about it so bungie nerfed it. It was basically unparalleled so there was not point using something else.