My reference to 'not lifting a foot' was not towards M KJ, but towards the end state of all tier raids where they over time become solo content. As long as they are current tier, they should continue to pose a challenge to the target audience progressing on it. All numbers indicate that KJ was most definitely an outlier and has been called the most difficult encounter in all of WoW history. The 'bar' doesn't remain static within a tier. Both explicit nerfs (hotfixes, tunes and patches to the encounter) as well as implicit nerfs (perpetual gear accumulation of which TF is an essential part, new gear sources (Broken Shore, Argus) and facilities (Netherlight Crucible) and non gear power inflation (AP/AK system)), smooth lowering the bar inside a tier.