All this yak about characteristic impedance, load matching, and dielectric loss tangents (aka dissipation factor) applied to cable in the audio band is akin to applying special relativity when describing the point at which two cars will intersect on the highway
Tssk, tsk, Dpac996, really:).
What the audioholics article is/should be really implying is, for example, that connections are critical for, say RF (i.e. it simply won't work) and uncritical for audio frequencies (i.e. it WILL work -- but perhaps badly, i.e. with high losses and noise introduction).
Unfortunately, if you use a 50ohm cable on 75ohm connection you'll have reflections even at audio freq; if you create a highly capacitive interconnection, you may get oscillation, and will probably get attenaution of frequencies, even at audio frequencies; if you use additional conductors (say for shielding) you will change the electrical charactersitics of your connection and introduce shifts in the transmission; simple: if you use a thin conductor you introduce a higher resistance than with a thicker wire, and possible phase shift in lower frequencies vs higher frequencies -- even in the audible range (try it, it works!).
Etc, ad nauseam.
If I remember correctly, Sean works in RF applications, hence his comment:
Helping me to understand that all cables of reasonable construction and parts quality sound identical will make my life(...) SOOOOO much better
. How nice that would be!