I don't know. Some people are desperate to try anything that may help them. Depression and anxiety disorders seem to be on the rise, for whatever reason, so it make sense that there would be a rise in people (not-so-knowledgeable-about-dogs people) thinking a service dog would be an easy fix.
I have panic disorder with agoraphobia and my pup is hopefully starting her psych service dog training soon. I don't have PTSD, and I am constantly afraid that since I don't, if someone random person on the street asks me why I have a SD, I won't be able to explain adequately and the person will think I am a faker.
I emailed a local place during my search to find a nonprofit to help me train or obtain an SD. I got a very rude response from them stating that they only trained dogs for "veterans with REAL mental illnesses" (yes, they emphasized 'real').