Power Cable DIY - Please advise

I am an EE and have been in high end hi-fi for 40 years.  I am also the happy owner of the large QUAD ESL 2912 full range electrostatic speakers powered by dual Benchmark AHB2 amps running in mono.  I have to say the power cable thing strikes me as nuts.  What about the wire before the power cord? 100 feet of regular romex to your load center (fuse box) then up to the pole.  As long as the power can reach your equipment and supply the correct amperage what else could you ask for?  120 volts AC 60hz that is then converted to DC.  I will say the cords look cool.  The entire purpose of a power supply is to clean up the power and get is ready to be consumed by the downstream device.  Clean DC is very easy to "see" it is a flat line on an oscilloscope.  Batteries put out nice clean DC.  Many years ago we were building a "super amp."  Rather than bother designing the power supply we used 4 car batteries, 48VDC.  Great power supplies are totally sonically neutral.  Anyway just adding my two cents worth!