This is an aspect of the audiophile community, I've never quite understood. At work, we have clear cut engineering goals, based on customer requirements, we strive to reach, with empirical measurements of product prototypes. Whether it's loudspeakers or cabinets designs, we're optimizing for variables such as coverage pattern, sensitivity, long-term power handling, etc. It's a holistic, system design approach to the "product". We rarely even think about a lot of the metrics the audiophile cares such much about, except in the design of QC systems for End-of-line testing, to catch manufacturing defects. Most of these items, like various avenues of distortion, are designed around in the early phases of development, by simple mechanical or electrical engineering choices, such as motor design, suspension design, cone material choices, etc.

I just always find it interesting. No customer has ever asked me for the plot of distortion products vs freq for a loudspeaker in pro-audio. Or the metallurgic compositions of the tinsel wires.