The Paleo hypothesis is that all foods introduced or consumed in greater quantity at the dawn of agriculture are what contribute to chronic disease and food allergies/intolerances. Neolithic foods in general are what Paleo believes to be incompatible with the human body. But it is just a theory. There are many conflicting theories, this thread being one of them. I think your question makes a lot of sense, and it's basically in line with WAPF protocol, which works great for many who follow it.