I think you don't have quite all the story there.
Looking at one random story isn't necessarily going to tell you much. Here's some context for that.
Information Commission ruled that claims of harassment were "grossly exaggerated".
http://www.virology.ws/2016/09/01/trial-by-error-continued-my-questions-for-lancet-editor-richard-horton/
What are people complaining about exactly?
Well, what Sharpe is supporting doesn't actually work. And his group doesn't listen to anyone.
" The information released revealed that ‘recovery’ rates for cognitive behavioural therapy and graded exercise therapy (CBT/GET) are not statistically significant. There are glaring methodological and ethical problems with the study and the authors misrepresented their findings. "
https://meaustralia.net/2016/11/29/alem-matthees-how-an-australians-foi-request-busted-open-a-uk-science-scandal/
" None of the changes made to PACE recovery criteria were adequately justified. Further, the final definition was so lax that on some criteria, it was possible to score below the level required for trial entry, yet still be counted as ‘recovered’. When recovery was defined according to the original protocol, recovery rates in the GET and CBT groups were low and not significantly higher than in the control group (4%, 7% and 3%, respectively). "
" The claim that patients can recover as a result of CBT and GET is not justified by the data, and is highly misleading to clinicians and patients considering these treatments. "
https://www.tandfonline.com/doi/full/10.1080/21641846.2017.1259724?src=recsys
" The second threshold for fatigue had been lowered so much, they point out, that 13% of the participants were “recovered” by that measure before the trial treatments started. "
" Instead of responsiveness to criticism, some – not all – researchers have put massive effort into discrediting the whole community and rallying other researchers to their defense. It’s been a collective ad hominem attack. "
Again, this type of complaint is a way to keep you angry with these particular patients and not noticing what's going on in this particular type of research, and definitely not supporting other types of research.
" Professor Crawley and her colleagues [Sharpe is one of these -CE] have routinely deflected attention from the defects of their research by wrapping themselves in martyrdom, complaining vociferously that even the filing of freedom-of-information requests constitutes harassment—a preposterous argument, given that patients have a legal right to seek key information about publicly funded trials. And these researchers also frame accurate criticism as vexatious and illegitimate."
http://www.virology.ws/2017/07/31/trial-by-error-nice-rejects-my-foi-request/
More on these problems here: http://www.virology.ws/mecfs/
By the way, there's definitely a formal diagnosis, just there's not a lab test which, by itself, would be diagnostic. This is not different to a number of other diseases. This article in your comments is new, from 2019, so it's even after the IOM diagnosis, which is no longer a diagnosis of exclusion. The first case definition named CFS was in 1988. The one in common use when the PACE trial was being designed was from 1994 , although they didn't use that one. There were others describing a similar condition since the 1940's and before that it probably was difficult to tell from other diseases but you can find it in literature if you look. Another common definition is from 2003.
So yes, there are problems with definitions. But the problem is certainly not that a formal definition doesn't exist. Maybe Sharpe doesn't read the literature and doesn't know this. Maybe something else. But in any case that's his problem, although it is a disservice to patients. (You'll notice in the links that's one of the complains; his group uses the worst possible definition for the purpose of wanting to know if a treatment works.)
So what's some of this other research you should be interested in, instead? Glad you asked.
Here's a systematic review of poor NK cell function. It's not diagnostic as far as I understand, since other patients can also have poor NK cell function, but it's a definite indicator that something in particular is going wrong. And it's fairly well replicated for a field this poorly funded.
https://systematicreviewsjournal.biomedcentral.com/articles/10.1186/s13643-019-1202-6
There's this interesting work with a new medical device, a nanoneedle. It shows that when cells are stressed (have to do work), there's energy impedance.
And metabolism projects.
https://www.omf.ngo/wp-content/uploads/2018/11/EDITED-Maureen-Hanson-Metabolism-and-MECFS.pdf
https://www.pnas.org/content/113/37/E5472
But all these studies have limited funding and support (outside of a small group of researchers--which do have good support and respect of patients; they'll tell you and you can see this by looking up some of them on Twitter. Try a patient-supporting excercise scientist like Workwell foundation for starters.).
To get this helpful kind of research well supported, the patient bashing and White- Wessely- Chalder- Sharpe- Fink- etc. worshipping needs to stop.
And there needs to be dedicated specific support for illnesses which have been passively or actively neglected previously.