Why? Because the electrons are very, very tired and stressed after powering through all that resistance. Do you really want them entering your audio equipment in that state? Geeze, they'll be stumbling over each other, wandering into the wrong locations, and just generally making poor decisions. Your system will sound like 5 pounds of crap squeezed into a one ounce Dixie cup.
A cable like this one essentially gives the electrons a trip to the spa. Or better yet, to an all-inclusive resort in the Caribbean. They can spread out, have a nice drink, eat at the buffet, absorb some Vitamin D, sleep for a few days and generally just recharge their proverbial batteries. Then they they are fully rested and of the proper mindset, they can orderly march into the power supply and the resulting billowing of music free from layers of veils will effortlessly remove the haze from the glass on the sonic window -- and even throw open the sash -- so you are looking directly outside into the performance as the musicians intended it to be heard and experienced. Your mother-in-law will call from the other side of the world and ask what you just improved on your system, as she can hear it through the screeching of the ally cats that are fighting outside her kitchen window.
Honestly, I don't know how one can even assign a monetary value to cables like this. Like a puppy, they add so much to our lives and ask very little in return.