I just want to add that, while there are a lot of vile doctors about (as with any profession), I think that the poor quality of a lot of the research around CFS, and the way in which a lot of results are spun to them, does make it hard for them not to be rubbish with CFS.
They're not going to have time to look closely of critically at research data, but will instead work on the assumption that they can trust the more general reviews of information given to them.
Also, the biopsychosocial approach to CFS is shit for patients, but can also end up putting a lot of blame on doctors. eg: If a GP has been told that CFS manifests as a result of patients being encouraged into a sick role by their doctor, then that sets up a difficult emotional situation for them, and which which is likely to lead to some feelings of guilt and resentment (an there's also plenty of misleading research which could play in to any desire they have to blame their patients). Also... there's not much GPs can do for CFS patients, so that's not ideal either.
None of which is to say that there are not GPs who are just arse-holes, and behave in a repulsive manner - just that for a lot of okay-ish GPs who would normally be good, CFS is particularly likely to lead to problems.