[Texaggie79]

But say that you didn't want your minor child eating Snicker Bars, whose responsibility is it to prevent him from doing such?

Yes. But once the child was old enough to get out on his own. I would not have control. Worst case scenario, he get's a snickers. That's not all too bad. Change that worst case scenario to, he gets all the booze he wants, that's not acceptable.

[Phantom Lord]

No one is seriously suggesting to reduce the drinking age to 16 so your fears are unfounded.

As far as I know, there are only 2 things that an 18 year old can not do and that is buy alcohol and buy a handgun. All other privileges and responsibilities of adulthood are bestowed on them at 18.