I agree. Moralistic people want diet soda to have some sort of downside due to a feeling that they worked hard to lose/maintain their weight and therefore so sh

I agree. Moralistic people want diet soda to have some sort of downside due to a feeling that they worked hard to lose/maintain their weight and therefore so should everybody else. The problem is every experimental study finds diet soda is really zero calorie and without any major downsides, it's only the observational studies that are flawed in the way I described that ever find these sort of "effects".