This has been a very interesting thread to read.
DH has anaphylaxis food allergies. He has not eaten a meal in a restaurant for many years, it just isn't worth it as a simple error means he may die. He will venture into sealed supermarket sandwiches though, and is over the moon about the rise in veganism as it means they have greater choice of egg free options.
I have autoimmune thyroid disorder. I had the coeliac blood test and the gut biopsy as they were convinced I had that too. Both were clear, to my relief, so I then did am elimination diet and reintroduced one at a time. The difference in symptoms was obvious. As Pps have said, there aren't diagnostic tests available for everything food wise, this was sufficient for the doctor to recommend avoiding the foods that aggravated them.
So here we are. I know that if I eat biscuits, cake, cereal, bread, pasta, pizza, then all my joints become painful, I'm foggy and lethargic, I want to sleep for days, I get patches of eczema and blinding headaches that are untouched by painkillers. If I don't, I'm fine. None of this happens.
Unlike DH, I won't die if I eat it. So I'm prepared to risk eating in a restaurant or a catered meal. I ask to see the gluten free menu and then order from that. I expect every effort to be made to avoid cross contamination as it would be for any dish.
I make no apology for choosing to eat as I do. It's clear to me that there is a middle ground where a lot of us are falling, it does us harm to eat something so we avoid it. It won't kill us or give the life threatening issues that coeliac presents, but the results are sufficiently unpleasant and debilitating for us to make that choice. Finally you have the people who choose to cut groups out inconsistently. May be because they can tolerate a little bit, or they are choosing to deal with the repercussions? Or because they have self diagnosed when it suits them or because they are faddy. The rage seems to be directed at the self diagnosed and faddy.