Comment: "How about people try raising their children themselves for a change."
From the Centre for Science and Democracy:
"Soda and other sweetened beverages top the list [of advertising], with the top 10 companies [in U.S.] spending over $1 billion on beverage advertising alone." 
"Children are targets of nearly a quarter of the food industry's advertising budget. Research has shown that they particularly vulnerable to sugar advertising: they are more receptive to sweet tastes than adults."
How can Mom and Dad, or Junior, tell what is good for them when industry spends hundreds of millions of dollars to convince them to consume sugar when the continent is rife with obesity and diabetes. 
Oliver is not being an "idiot," as you suggest. Cigarette taxes went up when we understood how taxpayers were paying for the massive health-care costs of users of that product. The same logic should apply to sugar.