I don't blame high-end raiders for asking for consistency. It wasn't them who wanted all healers to be dumbed down- They did want AST to be more consistent and that is something I don't particularly resent them for, considering how frustrating perfect Balance draws affected Savage runs.
Imagine, you could get party wide 15% damage buffs for 30seconds (Then subsequently nerfed to 10% for 20seconds then down to 5% for 30seconds. And you could use Celestial Opposition to extend the buffs) , but only sometimes. It would break progression when you could skip whole phases, but only when RNG would allow.
I do agree, the ShB card system for AST was dumbed down and still frustrating, but it was much more consistent, at least. (Even if you still had to mechanically fish for certain seals, but the difference was minimal.)