A bit of a wild guess, but many of those look like self-diagnosing or "fringe" from folks dealing with autoimmunity issues. Is that right?
> but who have unwittingly entered into a predatory industry
How exactly is it predatory? Rheumatology, which rarely engages in "cures" and whose "treatments" are often an exchange of one set of problems for another (if at all), and yet never fails to collect on its patients, might well fall under that umbrella.