People who can participate (those with the skills necessary to manage more complex systems as he states in his blog post).

The scary part is it looks like wealth will be increasingly concentrated, and more and more people will fall to a level where what we consider basic needs in modern society (food, shelter, education and health care) will no longer be attainable. As the author points out, "it will be messy": Those societies usually don't end well.

>People who can participate

A diminishing pool of people to pay for stuff, not only hurts businesses profits, but also diminishes the pool of rich people (who make their money off of selling products, houses, services, etc to the masses).

Bingo! If humans are continually replaced by robots without being given an income subsidized by the benefits of automation, in the long run, the robots will have to be shut down because the humans can longer pay for the products!

You are missing a great deal of suffering in the middle. Decent hard working people can start dying long before the robots must shut down.