Atmosphere's quote above perfectly explains how directional wiring would hurt the sound. The current is alternating back and forth, not flowing downstream. His diode analogy is spot on: if the current flows better in one direction, it is restricted in the other; therefore, directional wiring will absolutely make the sound worse. The argument that just grounding one end sounds reasonable... or would, if anyone would explain why the grounded end hooks to the source, rather than the input of the amp or preamp. Of course, no one has mentioned this.
