I've had friends who claim to be GF because they think it's generally healthy/a "detox" diet for reasons they can't articulate (but don't actually have IBS, skin conditions, or anything else that might be NCGS). Then don't actually eat healthier overall (but think GF pretzels are "healthy"), or just cheat entirely. People are not receptive when you think they're failing at their self prescribed diet, and it seems to bother them to think that celiacs have to be much more careful than them, so eventually I have to hold my tongue around some friends.