Probably has to do with palatability. Like how full sugar Coke tastes great and zero calorie Coke tastes terrible. The half sugar half stevia Coke tastes better than zero calorie but worse than full sugar. They probably tested each food and detected the inflection point where taste scores started suffering.
Maybe it's Stockholm Syndrome of some type after years on the stuff, but I've come to love the taste of zero calorie drinks, and find the originals odd and unpalatable. Hard to explain, it's like they are thicker/syrupy? Even Mexican Coke.
I belive it's that syrupy thickness people that prefer sugary version like, more than just the sweetness.
Personally, after a long brake from drinking coke/pepsi I can't stand either the original or the zero. I seem to crave the taste sometimes, then I buy one(zero) and it's like "what is this? Why sweetness is literally the only thing that I can taste here?" It feels like they are doubling the sugar in comparison to how I remember it. Most likely it's the same drink, I was just used to the massive sweetener/sugar content before.
Agreed on zero being better than diet. They actually use the same sweeteners, but a different flavor profile.
FWIW, in the US at least, Pepsi Max also became Pepsi Zero.
I suspect both are getting away from the 'diet' moniker because of the fact that people not on an active weight loss diet prefer them, ruining the played out joke of 'haha he ordered 2 burgers and a diet coke.'
Turns out Diet Coke is actually a different drink. When they made it way back when with the previous genesis artificial sugars it tasted terrible. So they actually re-created the recipe for the fake sugar.
Coke Zero is the same as Coke but with newer generation Artifical sweeteners. That’s why many who like Coke end up not liking Diet but like Zero much better.
