I was diagnosed with CFS in 2014 using the CCC not the Oxford criteria by an NHS doctor, so I think the government conspiracy argument you present is a little thin.
Unfortunately the disease classification of "chronic fatigue syndrome" was most likely created with ulterior motives in mind — motives related to the explosion of new ME/CFS cases that appeared in the 1980s, which could have bankrupted or at least severe affected disability insurance companies who were liable to pay billions in disability support for all these new ME/CFS patients.
The beauty about the disease classification of CFS, from the insurance company perspective, is that CFS is categorized as a disease that can have psychological causes (unlike ME whose classification is purely neurological), and this simple fact is enough to get these insurance companies off the hook, thus saving them from paying out billions, because insurance company rules often stipulate that they are not liable to provide long term disability support for psychologically-caused illnesses.
More details in this thread: Fivefold to eightfold increase in the incidence of ME from 1980 to 1989
And if you are interested in the ICD disease code shenanigans that, even to this day, place ME and CFS into different ICD categories (with the CFS disease code still allowing for psychological causes), then see this post.
Basically, if you say you have "CFS", by the ICD definition, you are saying that your illness could have a psychological cause.
Whereas if you say you have "ME", you are stating your illness has a purely biological cause.