I've said it before, I'll say it again, nothing catches a nerf as a direct result of whining/complaining.
BO1 had sniping exactly right. If you want to move about with a sniper, put on fast swap and run a secondary. Maybe even Overkill if you want a little more punch. OHK weapons need careful balance - shotguns have physically limited range for example. Shotguns can NEVER compete at ranges outside of their domain, and anyone getting beat out at the more extreme reaches of what a shotty can manage fully deserve their death.
People have managed to overcome a sniper rifles short range balancing factors. That makes them unbalanced and in need of a tweak. Most quickscopers have bad KDs? Thats because a large section of them just want to score ridiculously lucky trickshots, or put themselves into impossible situations to try and score feeds, or are simply just bad kids trying to be like Grizz.
Then you run into a PROFICIENT quickscoper, and suddenly the gun in your hands is rendered irrelevant in ways that no other weapon (bar a shotgun inside its intended BALANCED range) can manage.
He was playing brutally bad players. Anyone smart would have avoided his sightlines, or pulled up somewhere, ADS'd at his hill and waited for him to pop his head out.
Anyhoo, IMO he mentioned the flaw in his own logic there - 'Learning Curve'. QS is something that can be learned, and something you can get proficient at. Once the proficiency is achieved, the weapons balance is out of whack. He calls them inconsistent - so are shotguns, yet they are physically restricted from operating outside of their intended ranges. Snipers aren't, and people have found out (and can LEARN) the workarounds.
Its true, he can pwn with any weapon he chooses. Plenty of people can. But the fact remains that when a weapon intended for long distance engagements ONLY becomes VIABLE, or even in certain situations EFFECTIVE in CQC etc, it needs tweaking. Sorry, but thats just how it is.