If you have celiac disease then you’re certainly not jumping on a diet fad bandwagon by avoiding gluten, any more than a person with a peanut allergy is jumping on a bandwagon by avoiding nut products. The labeling laws for both gluten and nuts make a lot of sense to me and I’m glad that they’re helping you.
However, if a new diet fad comes along advising most people that peanut butter is the leading cause of obesity I’ll probably dismiss that as a silly idea.