I wonder why......

If power cables offer such dramatic improvements (not saying they do or don't), why don't component manufacturers supply them as part of a component sale? All high end components come with power cords that can be disconnected. The cost of a mid level aftermarket replacement cord is only a fraction of what the typical high end component costs so if sound is improved so much, why wouldn't a manufacturer want to "improve" the sound of their components by providing an upgraded cord at the point of sale? 

High end automobiles (Porsche, Ferrari, AMG, etc.) are typically supplied with the best tires available on the market. Often these are specifically designed by tire makers to the auto maker's specs. This is to extract every ounce of performance from their product. If high car makers did what audio manufacturers did, they would be supplying their cars with average, run of the mill tires expecting the buyer to upgrade on his own. Wouldn't audio component makers want to extract the best performance from their gear?

The only thing I can think of is that audio component manufacturers don't think so called upgraded power cables are worth the added cost.

What am I missing?

J.Chiappinelli