The difference is that the income inequality damages society. He states as much right in post 9.
Versus what? Please specifically define "inequality", define "equality". How much time various workers spend dedicated to the job, how many hours they devote, how much studying they do on their off time, how committed they are to seeing the business succeed, how capable they are of helping the business succeed, helping the business grow larger, how much liability they take on if a problem arises, these all are a part of the equality equation.
It's very simple to decry "inequality" without actually discussing what it specifically is.
Have you ever gone through the process of starting up a business? Developed a product? Taken it to the marketplace? Taken on the responsibility of servicing the product?
And, there are some great examples of well run countries around the world. Germany has a high standard of living. Except they provide extra wealth for their citizens by sucking the wealth away from the rest of the Eurozone, the more countries like Greece, Spain, & Italy struggle to provide basic standards of living for their citizens, the Euro gets devalued, and because of that Germany's export market benefits greatly.
It also is the culture of Germany that has made them unique to stand out. They are a very obedient society, and they are very dedicated to knowledge and skill. They take far more pride in their work and their quality than almost any other nation in the world. They are generational - if your parents work the same line of work their whole lives, and you learn from them their knowledge, and carry on in the same line your entire life, you have such a better foundation for outperforming others in the same field. It's not coincidence that these traits have helped propel Germany.
Or take the Scandinavian countries who have bountiful oil resources spread across a small population. Same with Canada.
Many point to the worker conditions of Europe, the other side of the equation is their citizens learned not by choice to live frugal lives. WWII devastated the continent, all over citizens were poor, infrastructure was destroyed, resources were very limited. A lot of the success nations have experienced recently, has been a direct result of the population learning through force to live a cheap life, live an efficient life, that has carried over through today.
Bottom line, the issue of worker equality is far more complex than simply believing hard enough for good things and electing smart Democrats everywhere.