I absolutely do not believe ME is psychosomatic any more than any other illness. That does not mean there are no psych effects - there are psych effects in cancer, AIDS, MS, RA, SLE, heart disease, Parkinson's, Alzheimer's, etc. i.e. Any serious illness has some effects on psychological function. Patient care does improve when psychological issues are addressed in diseases where there is no fast easy cure - even those that can be effectively managed medically and/or surgically.
The problem is not the idea that there is a psych component to our illness. It's that the more important physical illness has been ignored. I know my moods are not what they used to be. That tends to happen when one's life is turned upside down and one has to transition from health to illness at a young age. On top of that, perturbations in the immune system will obviously affect psych function.
The sad part is that as patients we must choose between ignoring psych aspects or ignoring physical - neither is the right course. Appropriate treatment would involve addressing every possible treatable aspect of disease - without stigma. That is true in any serious chronic disease. Unfortunately, an ME patient who becomes depressed then is promptly filed in the depression bin and the ME diagnosis is simply abandoned as the doc now has a label he/she can use.