I wonder what the genetic factor is for stevia, because oh boy does that taste awful. Aspartame is unpleasant, but stevia is something else entirely.
About the only diet sweeteners that taste sweet to me are xylitol and saccharin, and they're hard to find outside their niches (gum/mints and coffee sweetener). Kinda sucks tbh.
I'm one of those and have difficulties with most bitter drinks as well so the problem compounds as I have to have more sugar than most to drink coffee or nonherbal teas. I found that the sugar free off brand winco red bull doesn't trigger the same sour/bitter for me which is great. I still stick with water, milk, barley tea, and hot cocoa (I make my own mix) for the most part.
I know lots of people claim that Coke Zero tastes "basically" the same as normal Coke, but to me it was literally the most disgusting soda I have ever tastes. Far worse than even Coke light for some reason.
For me it's an on-/off relationship over the years.
I usually am fine with the Diet Coke at McDonald's in Germany (it's cold), but not a fan of the stuff I buy in plastic bottles. I do like Diet Pepsi but not Max (I find it tastes very artificial). Coke Zero is so-so.
And the weirdest thing is that we have Fanta Tangerine, which they switched from sugar to only-as-diet a while ago and now I can't drink it because it tastes so horrible.
TLDR: Either my sense of taste is just broken or they're actually switching the recipes every few years. Or it is actually this phenomenon here.
About the only diet sweeteners that taste sweet to me are xylitol and saccharin, and they're hard to find outside their niches (gum/mints and coffee sweetener). Kinda sucks tbh.