The concept is offensive on multiple fronts, but primarily two. First, because the assumption must be made that the people subject to the ban are incapable of making the decision on their own, else they would decide correctly and the ban wouldn't be necessary. The second reason is because in arguably each and every case, the ban is levied in a manner that lies far outside the legislative body's intended power by whatever constitution that created it in the first place.
Our nation of states was created to be the ultimate safe haven of freedom; a nation where one's rights were not granted by the government, but enumerated, under the assumption that whatever higher power created mankind created him free - the concept of "God-given" rights.
And so, when some pompous fucking mouth-breather decides you're too stupid to drink sodas in moderation, and subsequently presumes to ban not the soda itself, but the container in which the soda resides so long as said container is greater than 16 ounces, those of us who still value true individual liberty - having successfully survived the pressure-test of the blood vessels in our skulls - wonder how that dumb sonofabitch doesn't get run out of town on a rail.
And that, if we're lucky, is how a libertarian is born. If you can look at that, and start to wonder just where else the Nanny State reaches, you're on the path. And if you managed to land here, allow me to point you in the direction of those whom I admire most, and show you what a libertarian looks like when they grow up. Go there and be educated, because they can follow the thought all the way through to conclusion:
When you pass a law, you are effectively saying "This thing is of such momentous import that, if you do it (or don't do it, whichever,) we will compel you with force, and will back that force with the guns of the state. This is something that is so important that compliance is worth, push come to shove, shooting people."
It's a sad state of affairs - not to mention scary as hell - but the reality is right there in black and white. The Nanny State ends with a gun in your face, far too long after the time to ask if maybe we've gone too far.
Welcome to the club. We have t-shirts.