The appearance of a product, its reputation and other factors can certainly influence how we perceive its performance. It has been well proven in science that it is very useful to evaluate all manner of things on a blind basis in order to eliminate or minimize subjective factors.
However, people in the audio world often have a very limited black or white view of blind testing as if there were only one kind. ABX is only one particular form of blind test. Double blind isn't the same thing as single blind. There is a continuum. How exacting one needs to be depends on what one is trying to prove or accomplish. (Think of it as a number. Sometimes "about 3" is good enough, other times you need 3.14159265 - or better - for a calculation.)
If I am buying something for my own use, I only need to compare until I am happy. That may not include an effort at blind comparison - or may not even include a comparison at all!
The catch is that many audiophiles like making declarations of universal scientific certainty from casual or poorly conducted blind tests.
The often heard "I had my friend swap wires and I could hear the difference so that PROVES there is a difference in cabling" is a good example. It is a perfectly valid test for justifying your purchase of a particular brand of something, but it is hardly something you base your next peer reviewed article on for a science magazine.
To be honest, well done, tightly controlled double blind tests in the audio world are very hard to set up, and as such rarely done. Almost every one I've ever seen has enough "wiggle room" in it to allow an out for any party that wishes to disagree with the results.
