I think the authors are suggesting, "people are not being paid in line with what they produce."
I think the chart may show something else, which is "an increasing amount of work is being automated (and goods are produced by no one in particular), and this benefits owners rather than workers."
If I make widgets and you build a robotic cog factory, why should my wages go up?
Does the local community deserve to benefit from the automated cog factory? Does the state? Do all Americans? All humans? Those with coercive power?
It bugs me sometimes that you can argue "let's all share the wealth" but do it in a self-interested way by making a choice about who deserves what.
This article claims that without some kind of vivid lottery capitalism that makes people think "I'm not being screwed, I'm a temporarily embarrassed millionaire" people might become jaded regarding a US-style economy and choose a more socialized system that produces, for example, Germany-like income distribution rather than US-like income distribution.
Economies produce what they are designed to produce. The design and implementation of the US economy has been captured by capital, and produces results optimized toward the advantage of capital. That's a brittle situation, and a "gold rush" is a cynical response.