The thing is, there's a sliding scale to that: to me, every cable that is simply plugged in is faulty - to most people that would be a very subtle fault, but I have spent 30 years learning to listen for, and, yes, hear the audible artifacts of that "fault".
Why can that be a fault? Well, there are some excellent books investigating the nature of electrical contacts, and it's a nightmare world at the microscopic level, at the metallic boundaries. I didn't start by reading that material, but found them in the end through my researching of what was happening.
Of course. conventional measurements will never pick this up - but unfortunately, very unfortunately, there is just enough low level distortion being caused by these less than perfect connections to cause artifacts audible to the human ear. Subtle, yes, but they're the ones that do the real damage - for example, make that Zu speaker mentioned in another thread unlistenable to.
Where the subjectivists get it wrong is that they apply various loopy band aids to the situation - they alter the nature of the artifacts by doing so, but rarely ever "fix" it! ... QED.