Battery ground wire and hot wire section

I probably should let this go because I don't really have a dog in the fight. For those of you who use your frames as grounds you may wish to compare steel and copper in the attached table. Clearly copper is the better choice.
Electric Resistance – The Physics Hypertextbook
Steel 1.68E+06
Copper 1.66E-08
Simply put, steel has 14 times more resistance than copper.