There's no epidemic that can be ascribed to one food item in isolation, either. Why pick on soda? Where are the (reproduced!) studies that justify that? (Standing by for the inevitable authoritative-sounding pubmed link that actually proves nothing of the sort.)
Meanwhile, why should my health insurance rates go up because Dr. Joshgel is into cave diving or parachuting or enjoys the occasional track day in his GT3?
Or because someone else leads a sedentary life playing video games? How about banning those? There's no valid science behind claims of an "epidemic" of soda-induced obesity, but if you're going to generalize the argument to include all common causes of obesity, I'd respond by pointing out that there's certainly no shortage of studies showing the harmful effects of a sedentary lifestyle.
Rest assured, after the Dr. Joshgels of the world have come for my soda, they WILL come after something you enjoy. Maybe your steak, maybe your beer, maybe your guns, maybe your Playstation or your sofa. The slippery slope argument is a logical fallacy, but these people aren't logical. They're too busy being right.