Are marketing companies are taking advantage of people who are allergic to wheat?

Possibly: Pardon if I've commented on this before. Food allergies are becoming more and more common; the food industry has been regulated to identify and label ingredients that are responsible for the most common food allergies. Beyond just labeling requirements, some companies cater to those with food allergies; I would think this is a good thing for those affected, unless priced inappropriately high.