why do people feel the need to buy expensive cable

How about you buy what you like and I"ll buy what I like.

The term "expensive" doesn't really mean much.
All these responses and discussion over such
an ambiguous term seems rather ridiculous.
Please define "expensive" so I know what we're talking about.

$100, $500, $1000, $5,000, $10,000? For all I know
we may all be talking about different things here.
One person's expensive could be a drop in the bucket to another.

"Why do people feel the need to buy expensive cable?"
Should this read: Why do SOME people feel the need.......?
The answer could only be pure speculation.

The implication from reading this thread is that only stupid gullible people NEED to buy the UNDEFINED expensive cable. So why doesn't the original poster just come out and state that in his wisdom he is superior when it comes to HIS choices of cable and be done with it?
Rather than masquerading his obvious superiority in a thread question.

the reason...for the same reason most of us buy or want to buy expensive components. The desire is to obtain great sound. I spent on equipment at first and only thought about cables afterward, having been exposed to the idea that good cables made a significant difference, by reading about it here, for the most part.
I will add that it is easier to spend a couple of hundred on a cable than coming up with the money needed to buy better components, thus there is appeal in that sense. The OPs "expensive" is still undefined, if it is thousands then I have no idea why some people do it. Perhaps they have spent much, much more on their equipment and this the final tweak.
I did find that certain cables made a meaningful difference in sound quality and others did not. The price didn't seem to be the defining factor.
But I have not spent thousands on individual cables, so my experience is limited by my cheapness, about $500 and mostly less. Most normal, non audiophiles would consider that much spent on wires to be truly insane.

The usual reason audiophiles dismiss more expensive cables in a-b comparisons is because to be blunt, their systems aren't capable of clearly revealing the differences.

To summarize, if you can't clearly discern the differences between cables it is probably that your system isn't at the level of the cables, or your maybe ears aren't sophisticated enough to hear the differences. Really...seriously?