I don’t think their basic message of eating real food is wrong, but they go about it in a completely blinkered way with no concept of the real reasons people eat in particular ways.
It is my opinion that the problem won’t be solved by food tax, or calories on menus because the problem stems from that many people just don’t know how to cook, alongside prices of cooking equipment and basic ingredients. Many years ago, traditionally children were taught to cook at home with their parents, who learnt from their parents. It was also taught in schools. Then more and more women continued to work after having children, through choice or necessity, schools don’t teach children how to cook proper food and what constitutes a proper balanced meal, so combined with the rise of convenience food society shifted away from real food. How can people know what to do with basic ingredients if they don’t know and no one has ever shown them? And as an adult it’s all they’ve ever known and they’re tired and overworked so how can they learn now. Which is why taxing ‘bad’ food isn’t a solution.