@holmz -
I have no doubt that there are many using cables as tone controls, which simply goes to show: cables CAN/DO make a difference in reproduction.
However: everyone I know that uses high-end cables, regardless of position in their system, is attempting to do as little damage to their signal* as possible.
*the goal = neutrality/faithful reproduction
"Making measurable things referred to as faith is a bit of an oxymoron."
The Church of Denyin'tology uses measurements, based on 19th Century Electrical Theory, as the foundation for their faith.