Not many people have celiac disease, but more people are intolerant to gluten than you would think. My wife is allergic (been tested for celiac but doesn't have it). She was really sick all throughout her middle school/high school years because all she wanted to eat was pasta (like macaroni and cheese or something). We didn't meet until college so I'm just taking her word for it.
Until a couple years ago we just ate different things when we went out. She ate off the gluten free menu, and I ate whatever looked good. When she got pregnant we decided it'd be best if I stopped eating gluten too in case the baby had a gluten allergy so I started eating the same stuff she did. It's hard to completely 100% give it up because it's ineverything(flour to thicken soups/sauces/etc, flour coated fried food to keep it from sticking together, flour in almost anything that's baked, etc).
After a month of no gluten I had no more warts (I had one at the base of my pinky and one on top of one of my toes), no more sinus headaches, and next to no burping/farting - ever. I don't remember when exactly, but the first time I had a sizable amount of gluten after I stopped eating it was when I went to Texas Roadhouse with my mom for a birthday or something. I LOVE their rolls so I had a couple thinking I'd be ok because my wife wasn't there (and I'm not the one with the allergy). As soon as we left the restaurant I started feeling queasy, and we had to stop about 10 minutes later at a gas station for an emergency shit. My stomach was cramping hard, and I had this liquid monstrosity explode from my ass. If I eat any serving-size portion of anything bread or pasta now I reliably get the same effect.
I can't speak for all the hipsters or hippies or whatever, but I can tell you that I had never considered a gluten free diet before and didn't think it would do anything to me but be an annoying lifestyle change. I couldn't care less whether some salty assholes on the internet calls me a pseudoscience nut or hipster. The General forums are full of people who know everything and demean anyone or anything that don't agree with their world view so I don't bother viewing them often. Maybe it's an age/maturity thing... I dunno. I just wanted to drop in and say that after I stopped eating gluten I felt better. Itisa huge pain in the ass to be gluten free so I'm surprised that it's as big of a trend as you all claim it is, but that being said, I highly recommend trying it.