Soft drinks are little cans or big bottles of chemicals and flavoring. Studies have shown that consumption of soda can lead to obesity, hypertension, diabetes and possibly even heart disease. Any product that is capable of creating such a health hazard should have clear warnings saying so. I would even go further by saying sales to children should be limited.
At this time, sugar is not listed as a drug, so it doesn't warrant having safety warnings on it and its advertising, as is the case with tobacco products and alcohol products. People do know that excessive amounts of sugar are not good for them, and should act accordingly. The government can't regulate everyone's eating habits. However, sugar content should certainly be listed on products, for the safety of diabetics.