Picking winners and losers virtually always backfires. For example, we have very little information on what people will use for substitutes. Even if the government were successful at regulating or taxing away an unhealthy food or nutrient, there isn’t a way to guarantee that people will replace that food with a healthier option.
Different people need different diets based on their individual characteristics and that is something that has been well recognized by nutritionists and dieticians for decades.
When we warned people about consumption of animal fats years ago, the food industry hydrogenated vegetable fats to come up with trans fatty acids and now we are back to warning people about that. The focus should be on healthy diets, not individual foods or nutrients.