One of the best examinations of blind testing is: "Intentional Ignorance: A History of Blind Assessment and Placebo Controls in Medicine" by Ted J. Kaptchuk, published by John Hopkins University Press. In recounting the history he explores some of the nuances of scientific testing in general. This is a scholarly, peer-reviewed article, so there’s not much point debating it here. But he concludes with this:
"The adoption of blind assessment in medicine has had as much to do with shifting political, moral, and rhetorical agendas and technical research design issues as with scientific standards of evidence ... blind assessment has also been a vehicle to confer social authority and moral legitimacy ...
He writes that blind testing has a "concealed history" and that part of its "shadowy past is the intense fervor and absolute authority with which modern biomedicine advocates it ... the justification is ’self-authenticating.’ Concealed history augments the appearance of an obvious transcendent truth. Questions are discouraged. It becomes less something molded by interests, and more an unquestioned resource upon which any interest must draw, if it ever hopes for an accolade of objectivity."
The eternal chorus of those who demand that users here submit to blind testing are merely exercising their religious beliefs. If they were truly interested in science, they’d be discussing blind testing in scientific forums, where content such as I cited here is germane.