Similar wear-indicators can be found in a cheap paperback. When you lay it down on your night table, its spine buckles open slightly at the page you were last reading. You can pick up your story the next evening at this spontaneous bookmark. Wear encodes useful information. When two trails diverge in a yellow wood, the one more worn tells you something.
Worn spots are emergent.
They are sired by a mob of individual actions. Like most emergent phenomena, wear is liable to self-reinforce. A gouge in environment is likely to attract future gouges. Also, like most emergent properties, wear is communication. What Hill would like to do is transfer the environmental awareness communicated by physical wear into the ecology of objects in an office.