Why do people feel the need to buy expensive cable?
Because you get what you pay for - same thing applies to audio cable.
Truth is though there are different applications for cables. Interconnects being one, and speaker wire being another. There is such an abundance of information - and listener testimonial - stating that in the case of speaker wire, anything other than "ordinary lamp cord" is essentially unnecessary and indistinguishable audibly. The only thing one gets in this case is more broke.