I think it’s just a numbers a game and they screwed this one up hard. Too tough to begin with for your average raider and players struggling even just for AOTC to the point we are burning out before even starting mythic.
If not enough players are clearing the raid, or even attempting to raid, they reduce difficulty and keep reducing it until we eventually start seeing more and more players clearing, for sure they will have a KPI requirement on this, as in 10% of attempts should be clears, or 20% of raiders should be clearing bosses, or whatever. And if less people are clearing than they plan, nerf.
Back in the day they used different tools to help raiders instead of just nerfs, like the ICC and Dragon Soul damage buffs where over time the raid would get easier by applying a stacking buff each week, no need to detune the raid. And in DS you had the option to turn off the buff so you can still raid as it was for the first raiders who attempted the raid.
They should use something similar to this for all future raids instead of just trying to nerf the raid over and over. Sure one boss spell hits too hard, another is too weak, but that’s all about balance and if they allow us a stacking buff over time than it will still balance out in the end.