Well, I'm happy to hear your arguments, then...
It seems obvious to me that alcohol and cigarettes are not the same thing as telling people what to eat or feed their children. I'm happy to hear your take on this.
It also seems obvious to me that people in fine choose what to eat and drink. No-one ever put a gun to my head, for example. I absolutely agree that marketing influences choices, but only up to a point. Certainly the quantity is a personal choice. Giving Coke to your children for breakfast (I have seen it here in England) is a personal choice. A crap diet is a personal choice.
I also think that parents are responsible for their children. Marketing targeted at children is beside the point. Of course it will work, but again only up to a point: in fine it is the parents' decision to let anything go or to impose limits. I am a parent, I know but I'm also happy to hear your views on this.
And finally, it is also clear to me that blaming corporations (and behind them capitalism) for people's bad diets is a political stance because it fits the view that people are oppressed and victims of the system. But it's also the politically easy and low-risk thing to do because you don't scold people you want to convince to vote for you.
I agree that parents and children should be educated, that's even what I wrote in my previous comment. But let's also acknowledge people's responsibility in their life choices.
My take on the situation (at least here in England) is not that people don't know or that they are victims, it's simply that they couldn't care less.