Shadow AoE is a pain. Not because it’s bad number wise, but there’s so many things you have to do to figure it out, and you have to do that all on the fly. 2 targets is a different rotation than 4 which is different than 8. Targets that last 5 seconds is different than 20 seconds. Rotation when your CD is up is different than when it’s down. Etc. Figuring out what’s optimal takes a lot of on-the-fly adjustment and thinking, and even then, you still have a long ramp up, have to be stationary, etc.
Every class has to make these decisions to some extent, but it’s so much worse for spriests than most others. By comparison, on, say, a demo lock, it’s as simple as 2+ mobs? Implosion every X imps. On a moonkin, it’s as simple as 2+ mobs? Prioritize lunar eclipse over solar, and starfall instead of starsurge. On ele, it’s as simple as 2+ mobs? Earthquake instead of earth shock, CL instead of LB (and at a point drop flame shock/lava burst).
I get making AoE more than spam X (even if several classes can just spam a single skill, cough destro cough), but for spriests, it’s a level of convolution that’s just ridiculous.