The Coke Classic is still selling. Coke Zero has not replaced Classic. Both "no one bat's an eye" and your use of "most people" (even with the "I know" qualifier) are clearly extremes of both sides of the conversation being intentionally used. The fact that things like Diet, Zero, etc version of Coke and other soft drinks exist show people are paying attention to sugar. The fact that sugary products are still being purchased shows that not everyone has changed their habits.

Shouting extreme positions doesn't really move the conversation