Antipodes_audio, thank you for the comprehensive response.
Electrical engineers are very inclined to a reductive view of physics, dismissing many known issues as irrelevant at audio frequencies. By that they mean they are too small to be heard. Convenient when making a competent product, but how exactly do they know we can't hear them? As I say our ear/brain is incredibly sensitive to time issues, as that system is constantly separating out what we hear, its direction and its location, and that system is far more dependent on time-domain accuracy than timbral accuracy.
I am in agreement with this, up to a point. However, I would respectfully submit that there is a flip side to this line of reasoning. If we cant clearly draw a line defining the boundaries of audibility, we also cant predict when the point of overkill will be exceeded, and when the wrong parameters are being focused on.
It would seem safe to say that the chirp of a bird ten miles distant will be inaudible. Similarly, it would seem safe to say that one femtosecond of time smear will be inaudible, and will be swamped by other inaccuracies in the system as well. So there would seem to be finite limits to the extent to which reason, common sense, and technically informed a priori judgment should be deemed inapplicable to audio.
That applies to the cable designer, as well as to the consumer. How does the designer determine what design approaches to investigate, develop, and try out, when the point demarcating overkill for any given parameter is so nebulous? How does he know that he is focusing on the right parameters in the first place? How does he know that applying comparable focus and investment of time and resources to development of less expensive approaches wont yield results that are just as good or possibly even better? Reasoned, technically informed judgment, common sense, technical knowledge, and experience all have their place.
And along the lines of a comment you made in your initial post above, it would seem safe to assume that those qualities, and just as importantly the motivations, of different designers will differ.
Regards,
--Al