It is actually not low. There are numerous studies on how cutting out gluten has positive health outcomes for schizophrenia, epilepsy, and autism. [1,2,3] Not to mention numerous anecdotes from diabetics about how going on keto got them to reduce or stop using insulin.
As someone who has allergies and a ton of symptoms that were alleviated by cutting out foods, it is really tiresome to hear that it is placebo or it is psychosomatic. Before I knew it was allergies and had the test in hand, I just had to grin and nod along when someone said my chronic sinus headaches were essentially make believe. Now I have a piece of paper that confirmed just about every food I had cut out or naturally avoided.
You are clearly not familiar with the research in this area. People dealing with mystery symptoms that are cleared up by cutting out certain foods will generally be. Maybe hold off on telling them it is placebo?
1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6606425/