If Oliver feels so strongly about fizzy drinks he could simply stop selling them, but that would hit his bottom line so he'd rather gouge his customers to fund a campaign for a state-sanctioned 'level playing field' that will rip off his competitors' customers too.
To stop selling sugary drinks would require Oliver to show a degree of consistency and integrity that he has rarely displayed. Chefs are on very shaky ground when they start demonising a widely used ingredient like sugar (and, before that, butter) because it is likely that they use it more widely than most. If you're going to claim that sugar is "the next tobacco" you need to make sure that you don't lace your own food with it.
I haven't read Jamie Oliver's cook books, and I never will, but his cake recipe in the Sunday Times three weeks ago caught my eye...
Those 57.5g of sugar per slice amount to 14 teaspoons of sugar.* For the sake of comparison, a can of Coke contains 9 teaspoons and the World Health Organisation recommends that people consume no more than 12 teaspoons per day. Pucka!
If you can bear to take a grisly trip down memory lane, here is Jamie Oliver trying to be a lad in the early noughties, demanding a "greasy fry up" with "none of that low fat malarkey". Aside from being a reminder that Oliver has always been intensely irritating, it is a nice example of how supermarkets responded to the scientific consensus about saturated fat—a scientific consensus that has since turned on a sixpence.
* Ideally, the WHO think we should limit consumption to six teaspoons but they admit that this is based on "weak evidence".