Last I checked, nicotine isn't carcinogenic. It's the tobacco that kills you. Or, at least, there isn't enough research yet to say that nicotine alone is harmful enough.
So I may be playing devil's advocate here, but isn't this a net improvement over the last few decades? Kids getting hooked on something that's significantly less deadly? It's not ideal, sure, but it's better than a slew of cancer epidemics.
What is the FDA trying to achieve?