That's interesting. I think unfortunately words like "chemicals" "natural" and "processed" are thrown around so much, people don't really know what they mean, or what is important and what isn't.
On one hand, I think assuming that everything that's "not natural" is harmful is silly, especially from a scientific point of view. I think this kind of thing demonstrates how little most people understand of words we use all the time.
On the other hand, some additives/etc are harmful, and most "processed" food is full of salt and sugar and fat and devoid of nutritional value... and a common-sense approach to food, avoiding big lists of ingredients and sticking to more natural ingredients (by that I mean, fruit, veg, etc) - more food made from scratch from whole ingredients, is, I think, likely to be healthier. Most people don't have the time or inclination to read the back of every packet, and say, hey - is this weird sounding ingrediant harmless or harmful? What studies are there? Where does it come from? Most of the information isn't even easy to access if you want to, and even then, nutrition isn't an exact science and there's lots of unknowns. Avoiding everything that's "chemical" or "unnatural" or "processed" might not be the most scientific approach... but I think it would probably work quite well in practice, if your goal is to eat a healthier diet, and you don't have tonnes of nutritional know-how.