Except juice, which has the equivalent amount of harmful sugar. It's more because Bloomberg is a typical dickhead politician who makes policy only to further his own power.
Bloomberg was most certainly not trying to further his own power in this situation - he went to his assistants and asked, "What single thing is most harming our population's health right now?" And the thing currently at the top of the chart was super-large-sizes of soft drinks.
But, here is the thing - the United States (with the exception of Seat Belts, in which the NHTSA managed to link federal funding and increased safety), is typically not in the business of being a nanny state. The exception for smoking was that it was second hand smoking that was being legislated.
It's the reason juice is consumed by the occasional glass, and soda by the proverbial gallon, and why the latter is far more harmful than the former. And it's the reason there's a certain class-driven health problem around drinking soda.
It's also the origin of Dave Chappelle's hilarious 'what the fuck is juice?' joke. [0]