I've also never encountered a move in the three games of SC I've played over the years that required a different amount of shaking then others.
IIRC, either Nightmare's CH NBS K or CH NSS K in SC2 (or SC1?) caused a DOS stun that required 7 inputs. I don't think that applies to SC4 tho
Also, unshakeable stuns do offer guaranteed damage, and if you dont shake the shakeablestun you want to give them free damage instead of mixup? I know it scales, but sometimes it doesnt scale quickly enough, and there goes 35% of your life.
I know people are jumping on your case, and I ask this not in a facetious manner: what other fighters do you play?
35%? Almost any fighter I can think of, the average juggle or combo is 50%+. In quite a few fighters, there are death combos and infinites.
SC4's combo damage scaling is WONDERFUL. I love it. The stuns actually allow people to do nice long combos unlike SCs of old, but the scaled damage still keeps the game more about mindgames instead of turning into an all-out test of "whoever lands the first combo starter wins."