Not gonna defend blizz on that part, they just cant put multi dot class on a sweet spot, they just cant find it, and the worst part is that you cant really have a raid full of ST oriented fights cause thats trash too, you gotta put that cleave/aoe fight in there for the sake of variability, and thats when the usual multi dot classes start being an issue again, shadow priest has been the problematic child along with aff lock for way too long, i dont even know what to do with them, at least class stacking wasnt that bad this tier, not on Zul lvl at least cause that was absolutely disgusting.
More on topic, people need to assume their part of the fault when doing these threads and not just directly saying *hurr durr blizz sucks mythic is too hard*, i can assure you none of them has ever asked themselves what they can improve, if they got worse or what part of their strat they can change, cause thats not how mid tier mythic guilds work, they just blame it on blizz just like this thread, the cherry on the cake is that most of them cant even get good parses on heroic, and if you cant get decent parses on heroic (when its just tunneling), then theres just no way you perform on mythic, thus we have the 3/8M guilds forever stuck on ashvane for example.