Why do you think they advertise?
Falling back on individual responsibility might be popular but it is absolutely a cop out. We're playing a numbers game with public health in an adversarial environment. Relying absolutely on what individuals could or should do isn't going to help us win that game.
This is true even for those people who never question why they are purchasing food in boxes instead of actual food.
It is best to understand that people can make informed choices. It is very shortsighted to think that everyone is subject to the magical sway of marketing without a conscience or decision making abilities.
The existence of personal choice and individual responsibility don't make anything else that you mention disappear. Are you saying you want to increase behavior modification of people and somehow rob people of personal choice? That's what your words imply.