I think the shrinking middle class has more to do with our monetary system than technological advancements. It is well understood that devaluation of money through inflation is not an effect evenly distributed. It is a significantly larger effect the further from the "source" of the inflation an individual is in the economy. The middle class and poor are quite far from the source.

There is also the "feedback" of wealthy individuals being able to more effectively lobby the government to pass economically favorable legislation for themselves. I believe this is a very strong factor in the shrinking middle class as well.

Although the author gives statistics showing the increase in wealth disparity, there seemed to be little evidence supporting the thesis of the article which is that technology is driving this phenomena. Also, more compelling data would also be showing a period in US history when the middle class was expanding and then began to decline. Then the author could give a better argument to what changed. Though, I guess technology is always "advancing" so in that sense, he/she would never be able to find a proper place in time. Maybe "the dark ages"? :)

tldr;? Liked the data showing the increasing wealth gap, felt the argument that it is fueled by technological advancements to be weak to nonexistent.