I see your point, but I don't think changes are made due to "Complainers'...rather metrics they have showing how the perks are used in game on a daily basis.
Amplify, from my experience, was simply a broken perk, and I as I broke down on a thread I wrote... the only perk in the game intended to counter another perk rather than something in game.
I guess we will just have to agree to disagree on this, and that is fine being the ultimate nature of Forums. But Having seen DS in previous games, it was hardly a game-breaking perk, nor did it throw off balance in any way. It simply countered something the game already had, footsteps. Those who were aware and didn't overly depend on just one sense never had an issue with DS users. It didn't need a counter. Amplify took something in game and blew it up to ridiculous levels.It threw off the balance of the game incredibly.
As it is now, Amplify still counters DS, but not to the degree it had before. Balance is key in FPS shooters, and what keeps it challenging and fun. Not much fun to be had when a perk automatically pinpoints an enemy...providing direction and distance.. allowing people to simply sit and wait.
I am all for audio cues in game. Black Ops had some of the best Audio Cues...different surfaces had distinctly different footstep sounds. Each game has taken it to different levels. I think Audio cues should be present. But Amplify took it a step beyond, and for minimal cost to the user provided way too much of an advantage. I am glad to see they are balancing it. For those who know how to use it, it will still be a highly effective tool.