Here’s the thing: We’re not comparing AOTC completion rates to an unknown metric. We’re comparing them to historical numbers; we know what has been done in the past and what’s being done in the present.
What’s going on in the present marks a change from the past. No one that I can tell is asking for AOTC to be nerfed to something it’s never been before. What’s being asked is that it be put back in line with what it always was from the outset of the game until the rollout of BfA.
With BfA, the encounter design team and/or the game director decided that AOTC needed to be toughened up, and when completion percentages are compared like-for-like, those numbers got cut by two-thirds. I’m saying that’s the wrong way to go, for two reasons: One, it represents a huge increase to content difficulty for content aimed at the Heroic tier (when no one was beating a drum asking for that to happen), and two, if one of the goals is to get people into the entire raiding scene, from LFR to Mythic, making the early tiers of progression raiding 2x-3x more difficult seems like the wrong way to go about it.
To recap, no one is asking for a nerf; they’re asking for a reset. And that’s a very important distinction to make.