I imagine you also lived through the 1990's and the rise of the "alcopop"? Did watch a documentary about it a few years ago, it wasn't initially to appeal to teenage drinkers (although that it was it became), it was originally a way to strike back against the "rave scene" and perceived use of other methods of "enjoying oneself".
So, to counteract the drinking of water (bad), and not alcohol-based drinks, the "industry" created the alcopop, which I am pretty sure led on to the creation of the "energy" drink.