I think the reality is that many who maintain there are no differences between cables (or other things in audio) don’t want to deal with the personal and/or financial implications of such differences being real. Denying differences are possible is their way of avoiding those implications.
To the contrary, I think that often (though not always) the reality is that those who maintain there is a difference between cables, etc. and who profess the superiority of one over the other have arrived at their decision in an almost completely subjective manner. The only objectivity in these cases might be the reliance on technical measurements by the manufacturer or third-party entity.
In my view, it really shouldn’t be all that unreasonable to expect that this same someone who professes superiority could detect whatever it is he/she feels is superior in a blind test.
Question becomes, why wouldn’t you want to subject yourself to a blind test in order to further confirm your belief?
EDIT:
It should also be noted that in no way am I hypocritical in this regard. If one refers to my posts at the time I obtained my Yggdrasil, I compared it my my Oppo and Emotiva. I didn't just haphazardly arrive at a conclusion it sounds better, I proved it to my satisfaction. Part of the proof process was bling testing.
