It is often a mystery to me why mediators will make statements about the practice of conflict resolution that are unproven or even inconsistent with research. Now, after reading "Why many clinical psychologists are resistant to evidence-based practice: Root causes and constructive remedies" (Clinical Psychology Review), I think I have some clues. Although the article is focusing on therapists, I believe it may relate to the attitudes and opinions of some conflict professionals.
The article does not help much to explain why mediators will make assertions about (and Tweet and reTweet) research they have not read (getting their information only from abstracts or press releases), but it does perhaps shed some light on other of their claims.
The authors in the article list six reasons for resistance to EBP (evidence-based practice). One of them is "naïve realism, which can lead clinicians to conclude erroneously that client change is due to an intervention itself rather than to a host of competing explanations." From the section on naive realism (cites removed for ease of reading):