I deliberately chose not to use the word "belief" because I think it immediately puts people in opposing camps. It implies at a dogmatism on both sides, that I'm hoping to avoid.
Fair enough, feel free to substitute 'view' in place of 'belief' in what I wrote.
If it makes it easier though I'm happy to reword the question something like this:
"Each individual's experience has led them to believe that power cables either do or do not make a difference. Is there anything that you could imagine experiencing that would lead you to change your own belief "
That's true for many but not all 'non cable sound' people. Some form the view in absence of experience, because there are no measurements and no mechanisms known to them by which cables can sound different. Put another way they know there can be no difference so there's no need for them to do that particular experiment.