I'm also against just out loud stating that diet soda is just as bad as regular soda. That will just make people go: "well, if I'm drinking soda, I might as well go pure sugar because diet soda isn't any better."
At least with diet soda you can still into ketosis. It's less carbs by default..
The point is that if you're worried about weight loss/low carbs/ketosis, then you're better off never drinking any type of soda, instead of halfassing it by switching to diet soda. All of it is shit for your body.