Just the other day I joined a vinyl forum. I had found a topic in it that I was interested in, so I registered to be able to join the conversation. As I started reading some of the member's posts, I came a across a long sarcastic thread against audiophiles. In response to someone's already sarcastic comment, someone wrote, "That's nothing, some people out here in California actually believe the choice of cables can improve sound!"
But that is just the thing, it is perceived as a BELIEF, when it is, in all the cases I know of, empirical knowledge. People have experienced the difference a particular cable has on sound, which they then tend to prefer or dislike.
You may not have experienced this things yourself because you have not done a/b comparisons, have not trained your listening habits to pay attention to the qualities of sound that are affected by cables or your current system can't resolve the differences between two cables. These are all possible, but that does not mean that others can't experience, appreciate and even seek those differences. I, for one, have never experienced what happens in a cyclotron, but I do not pretend to deny the realities of sub-atomic physics because of my very limited experience.
I remember when I started playing around with cables I thought there would probably be some differences because it seems logical to me that different materials and geometries would certainly affect the qualities of sound, but I was hoping those differences would be slight, as I did not want to open another avenue of possible improvements to my system. The cables in question were Analysis Oval 9's vs. Radio Shack thick copper speaker cable. Unfortunately, even with my very modest system back then, the differences were huge. In the decade since, my system has evolved a lot and cables have always been a careful consideration.