Your link makes all the same points we've all heard before. Where it completely misses the point is that this isn't a mere productivity upgrade; we're going to reach a point where robots will be able to do some jobs better than a human could. There will be nowhere for (some of) these displaced workers to go. Everything they can do, a robot can do better. It will start at the lower end of the spectrum, from unskilled workers, moving up to more and more skilled workers as automation and AI advance. Obviously, I believe that this technological advancement in and of itself is a great thing, but we will have to find a way to manage the issues that come with it.