The problem is always in my experience misdiagnosis.   A properly diagnosed CFS sufferer - and that means using proper criteria such as CDC Fukuda et al, not the Oxford Criteria and its derivatives - is likely to "hit the wall". What these programs can do is sort out the misdiagnoses and put them on a better path

Sadly the failures are likely to be the ones correctly diagnosed.  Nothing wrong with programs such as this, and even CBT - but truly they don't address CFS only the misdiagnosis of the illness.  

I remain - as a sufferer - convinced that is a cluster of physical illness whose diagnosis and treatment the medical profession have made a total dog's breakfast of.  The current best hope is to try to provoke a spontaneous remission by good diet, sensible pacing, lowering stress and any sensitivity or allergy assault and very carefully applied exercise that is not progressive in nature but rather , stable. - But keep trying and don't give up

I have never felt that the Lancet has abandoned a deep seated belief "IAIYH"