As a simple experiment, put your foot up on someones desk at work.Show them your new socks or the holes in the old ones.
You may not live to tell us the results.
We know 0bama would never walk a dog, but he still walks. No telling what is on the bottom of a shoe.
I agree, and at the very least, there is grit on the bottom of the shoe. On the desk it becomes sand-paper with upwards of 150 pounds of pressure behind it.