Precisely.

Say for example you expended a lot of your time and money in organising a watertight 100% conclusive double blind test next week, how many naysayers would be banging on your door begging to buy a cable from you the week after to recoup your huge outlay?  Errrrm, none.

If they cannot hear the differences now, they certainly won't hear them then, no matter what form of 'proof' you lined up, be it DBT listening tests or some pretty wiggly graphs.