> the consensus is that this is a physiological disease with an unknown mechanism

Can you point me towards a statement of that consensus?

> I don't know where you get the idea that the null hypothesis for the cause of any set of symptoms not explained by known biomarkers needs to be "psychosomatic disorder".

I didn't say that, and in particular never used the words you put in quotes and attributed to me. However, I'm pretty comfortable with what I did say: absent evidence to the contrary, a collection of self-reported subjective symptoms with no apparent physiological counterparts is significantly more likely to have a psychological origin. Can you say more about why it doesn't make sense to you? Or point me towards the evidence specific to CFS/ME that makes you think it doesn't fit that description?