As mentioned in the original post other things can be questioned, I think Cables act as something of a "boundary" issue for people. We all know that transducers will differ, there is not much to believe or doubt. Amps and Dacs may objectively differ in performance, while the threshold of audibility and correlation to subjective preference may be in question, it's pretty easy for most people not to question the possibility of differing performance. Cables on the other hand seem to offer a challenge for many people, it's simply dificult to accept that differences exist given so much ground to doubt on. Most people don't question what grounds their beliefs and values, cables stand out as the first boundary that force a subjective justification for belief and an obvious place to start scepticism from.