why do people feel the need to buy expensive cable

It seems that the OP got more than he bargained for, soliciting input on the perceived value of cables.  FWIW, I have really tried very hard with lamp cords, DIY cables but there is a limit (mechanical, metallurgical, chemical) that is reached when you get beyond a mid level system.

Not unexpected, some religious wars and some kind of flaming started...some pointed comments are refreshingly true, some soaked in sarcasm on the other hand made my day! I needed a napkin.

Similar to Amazon comments, posters should have the "verified purchase" icon so it would be easier for the casual peruser to see who has bought some cable of value ($-wise, not always sound wise) and who has not, who has a great system and ears, who has supposedly a $24k cable and some JBL speakers (sorry, couldn’t resist that).

Let your ears be the judge and, as always, the beauty (of the sound) is in the eye of the beholder and taste certainly differ.

What’s next: does the thickness and the polish quality of your amp front plate make a difference?

I beg to differ. 

1.) Good cabling makes a good design even better. Cabling are sometimes misused to correct deficiencies or to enhance a certain range. Until one has experience really great cables, I don't think one can make the statement you just did. Why on earth would most of us who bought more expensive variants, want to throw money?

2.) >>  (eg: anything that is not mass market tends to have design issues). 
there are plenty examples in the mass market industries like the car industry that shows design flaws. Back to the audio industry: Let me ask you how many models of the high end series of mass market brands like Sony, Denon, etc proved to be keepers? Yes, just a few. Heck, even some of Nelson Pass' designs turned out to be just ok.
Your assumption that great design and quality is correlated to the quantities sold - and indeed this triggers the economy of scale, resulting in a lower price- is not always correct, it affects but it does not dictate.
I would say quality control is harder to achieve with some hand made equipment/device if a stringent QC process is not established and rigorously followed.

I have mentioned in another thread that the Mogami cable, widely used in pro-audio, offers excellent value/money in the entry to mid level market segment.

The correlation between the cost of cables vs the cost of critical components needs indeed to be monitored. Lars of NordOst used to put a NordOst Valhalla behind a RadioShack level receiver to prove his point that a (power) cord does make a big difference. It is of course totally up to the owner to decide if he/she want to spend 5, 10 or 80% of the total budget in cabling. The same rationale goes for the patron in a restaurant spending a relatively big portion of the bill on a great bottle of wine rather than on the entree. Just suggestion that the overall meal experience could be better, e.g. not spending on a Chateauneuf-du-Pape, rather on a chateaubriand, not ordering a 30 yr port after dinner but instead a better dessert,...

Each to his/her own.