A very valid question indeed.
All this fuss about cables, yet the same people will buy any another component, take it out of the box and bung it in the rack no questions asked. How do they KNOW that what is sitting on their shelf has exactly the same performance curves as published in the literature? Do they measure to make sure? Are you at all certain that what was reviewed in the mags is the same article before you? I am not for one minute even remotely suggesting that specially selected samples are sent for review of course.