Your dogmatic opinion - as far as I know you did not carry any significant experiences on this subject, neither studied the subject. Many people consider that cables are directional because of metallurgic and manufacturing reasons independently of ground wires - for example some non shielded SE cables are directional. Many people consider speaker cables are directional.
We still do not have a reasonable scientific model why power cables sound different - the best scientific approach I have read calls it "placebo effect".Why should we consider that the effect of a fuse, that accepts noise signals of much higher bandwidth and amplitude than audio cables is well understood?
My conrad-johnson amplifiers use Bussman KTK-2 fuses in the B+ line (factory fitted, not tweak). As they are expensive, I have tried another type of less expensive fuse for initial tube burn-in, in this phase a poor tube can easily blow the fuse. They degraded sound quality.
IMHO most of the time calling a tweak as silly before analyzing it is premature.
Much of this criticism is technically fair. I was making an assumption about efficacy prior to personally conducting A/B tests. But even the most ardent subjectivist, science-based argument-ignoring part of my audiophile brain has limits in time and in personal interest and in the suspension of the application of the “straight face” test.
It would never occur to me to taste test on an A/B comparison basis different English Breakfast tea bags from the same box of English Breakfast tea bags. Am I merely assuming there is no difference in subjective taste among different bags of tea in that box? Yes, I am.
And even after all that in reply I am not declaring in any way that Audiocrack is wrong or that there is no directionality to the sound qualities of fuses. I don’t know. I have not performed the comparison. My assumption might very well be wrong. All I am saying is that I personally have no interest in conducting such an A/B test, and that, as Marc states correctly, I am skeptical.
