[rattlsnak]

The DND feature can be turned on or off which makes it a choice. No different than making the choice to pick up and use the phone when you shouldn't be. There would be no way to make legislature to make it automatic as there are way too many parameters. It is triggered by speed as the phone assumes you're driving if it sees certain parameters. So what if you're on a bus or a train, or riding in the back seat of a carpool or such..?
It will always be a choice and be that will be unfortunate for some.