It is not crazy at all. But realize that patients that suffer from these disorders have likely been hounded for decades by doctors, employers and various government workers. I think they have heard all the variants of "I think you are faking it" that you can ever think of. That doesn't excuse the patients death threats, but one should thread carefully.

There are also a lot of diseases that were thought of to be psychosomatic that turned out to not be such as peptic ulcer disease. There is also gender bias in play. Pain or illness affecting males are more likely to be classified as physiological while the same thing affecting females is more likely to be classified as psychological.