What happens on S4ME really has no parallel. I'm sure that surprises many - isn't academia where knowledge is formed, where ideas are debated and tested? Well, not so much. The only real comparison would be journal clubs. Critique occurs in certain prescribed forms, such as letters to the editor, and there are unspoken boundaries as to what can & cannot be said. (And you might want to be judicious as to whom you criticise, as they might well be your next "Reviewer 2", or worse). Most will not be at all used to the kind of critiques, written in blunt language sans the usual academic style, that often do appear on S4ME. While I very much enjoy having ideas refined by fire, and always have done, it's not a common attitude.
Many researchers in the ME/CFS space are also, frankly, third-rate, and some of them are using ME/CFS to pursue their own little niche interests (there are maybe 3 or 4 groups doing genuinely good work, and even some of those don't always have a very good handle on what ME/CFS actually is & is not). Some of the third-raters have been raising funds for research of likely extremely poor quality; these people are not going to care for critical scrutiny.
Most people would be amazed at how petty, prickly, small-minded & trivial academia can be. Then there's the "publish or perish" culture that has taken hold, the emphasis on quantity of research outputs, as well as the commercialisation and poor treatment of staff - I'm told some of the UK's most prestigious universities are now reliant on staff on zero-hours contracts - and, as a poor choice of career these days, there's increasingly a dearth of first-rate minds, who tend to end up in tech or finance.