In short, a caffeinated alcoholic beverage targeted at "young adults" is "adulterated," while exactly the same beverage targeted at middle-aged drinkers is not. The FDA is not really banning drinks; it is censoring speech.
He follows up with some parting words:
For those who are worried about what will happen when their stockpiles of genuine Four Loko run out, BuzzFeed has instructions for making your own at home. For those who want to stay awake while they're drinking but would not touch a declassé drink like Four Loko with a 10-foot tongue (why am I thinking of Freddy Krueger all of a sudden?), New York Times restaurant critic Frank Bruni reviews hoity-toity coffee cocktails served by boutique bars in Brooklyn and Manhattan. Something tells me these drinks, despite providing a pharmacologically identical experience, will never inspire a moral panic like the one that drove Four Loko and its ilk from the market.