Isn't that part of the reason why Silicon Valley jobs pay as well as they do - to cover the costs of living in the area, as well as cover the various inconveniences like commute?
If somebody wants to work remotely, draw the same salary while also benefiting from living in a state with a significantly lower cost of living, would the company have reason to reduce their salary accordingly? All other things equal, they would be less valuable compared to someone who could still drive in to the office on certain days where his physical presence was required or at least appreciated.