It is easy to forget that not that long ago, There was no legal age limit for consumption, and when it was instituted, the age was much lower than it is now. Thanks to the previously mentioned Nanny State, the legal age has steadily increased, producing what i believe to be a more dangerous culture of consuption, not a safer one.
Personally I like the German model:
Drink at 16, drive at 18.
That way kids have a few years to learn their limits before getting behind the wheel. Oh, and they also TRAIN you to drive there, as opposed to handing a license to any blind, 1-armed monkey with a pulse.