My money is on hammies thinking "Gluten free is just a whole new range of foods to eat, I'll spin it that it's actually healthier than regular foods, as an excuse to eat them!". IIRC, It's actually worse for people who can stomach gluten. Because Whole wheat is also a major source of dietary fiber, which the bowels need to work properly. Which is one of the many things you can't have going gluten-free.  And therefore can lead to unnecessary bowel-cancer risks in otherwise healthy people.