You've seen those links? Have you read them? The third one is a link to the most extensive literature review ever undertaken, and their conclusions were strong enough for them to state flatly in the abstract that this is not psychological or psychiatric.
https://www.ncbi.nlm.nih.gov/pubmed/25695122
I'm left wondering exactly what it will take for people to back off this stuff about this being a psych illness. What evidence exactly is required? The volume of studies indicating objectively measurable biological abnormalities is massive. Many are unreplicated due to longstanding funding issues. But while I think most reasonable people would agree that psych issues and/or stress are capable of causing a number of physical issues, I can't imagine we'll ever see anything that suggests that psych issues could possibly come close to affecting the body in the severe ways that Myalgic Encephalomyelitis does.
https://app.box.com/s/9s4coexxtys5bnz33i6gvqqygu67ex5o