KingAce
HERMITISM
As i have said previously in my posts, its was a safer option to take if you did not know your opponent's intentions. Because you would still get the 50/50 mix-up on your opponent instead of the guarantee, or force your opponent to defend as your are on advantage. While a full step is like betting the house that your opponent would whiff; step-g was a safer bet. Smaller reward but a safer bet and a potential reward all the same.
We used full step as well when we predicted a non-tracking vertical or in a step set-up. It is obviously superior to step-g if you guessed correctly but if you played people who actively killed your step; you would be hit by CH step killers constantly and put you behind your opponent quite quickly.
With step-g, your opponent is not being rewarded as much from his slower big damage step killers and as such you will not fall behind as quickly.
And step-g was part of how Safemare in SC4 operated.
And with step-g, you can minimize the risk of stepping TAS B. With full step, though I believe you get 1A or 44B (or back throw, i cannot remember) guaranteed, if you mess up; you are going to get hit for a ton of damage. With step-g, I believe you get 3B guaranteed and will still block TAS B if you mistime the step.
Like I said you would have to show me.
From my understanding NM's eventually began to rely more on step attack than step g. Yes Step G is a safer option, but it gives less opportunities for whiff punishment. This is why I stopped using it for whiff punishment and simply used it for throw/mid setup. If you want to maximize damage you risk step attack.
Bottom line Step G was terrible for whiff punishment as Nightmare you got very damage from it. TAS B is your example which you can't 100% verify. But you won't whiff punish BB or 3Bs or other relatively fast horizontals with 3B/33B using it.
Hell that's why I didn't even bother with QS4G. If I wanted to step G a better option would be to backdash G. Because at least in that instance you fully backdash, as opposed to canceling step by pressing G and sometimes having horizontals track the evade.
So to me step G wasn't a big deal. Safemare was a strat for specific match-ups, but I hardly saw it utilized later in the game's life. NM players took more risks.