I don't think you understand the difference between a complaint and a genuine issue with the game. This is where Ghosts failed miserably and only a minority of a minority of people want to see Ghosts TTK as standard in core game modes. It boils down to this:
You think you can react in under 1/10th of a second? Oh wait, the server already registered you as dead because you died in the time the data saying that you were getting shot spent reaching your client. Add that to the fact Ghosts wouldn't give you the ping bars to actually let you decide if you had genuine lag. You end up sitting on a '2 bar' connection you don't even know about and get insta killed in every engagement.
And if you only play Hardcore then why do you even care? Core is completely different mechanically from Hardcore. It doesn't even affect you?
Sledgehammer has even come out and said they want a TTK closer to Black Ops II. That should tell you all you need to know.