Avoiding gluten isn't a dumb fad, some people have a gluten intolerance. That's like saying it's a dumb fad for lactose intolerant people to avoid eating dairy.
There is the population of health weirdos that insist that gluten is just evil and got enough mainstream traction for enough time that people that couldn't actually digest gluten finally got some love and now gluten free options are more abundant.
Avoiding gluten isn't a dumb fad, some people have a gluten intolerance. That's like saying it's a dumb fad for lactose intolerant people to avoid eating dairy.
There is the population of health weirdos that insist that gluten is just evil and got enough mainstream traction for enough time that people that couldn't actually digest gluten finally got some love and now gluten free options are more abundant.