Is the Future of America's Middle Class in Danger?

America's middle class is shrinking. From President Obama to Nobel laureate Robert Shiller, many prominent figures have raised concerns about the growing income inequalities in the US and called for a change. In a recent article, Henry Blodget of Business Insider boldly criticizes what he considers to be one of the major factors driving this inequality - the frenzy of focusing on short term profits which often comes at the expense of employees.
Blodget claims that these profits are largely driven from paying the least possible to the average employees, and while this obviously hurts those employees it might also hurt the companies in the long run.
As he argues,

This behavior is contributing to record income inequality in the country and starving the primary engine of U.S. economic growth — the vast American middle class — of purchasing power.

It is not a law that they pay their employees as little as possible. It is a choice.

The US has long been envied by the rest of the world for its median income and purchasing power of the middle class. However, it seems that this great purchasing power is disappearing, which could have great implications on the world as we know it today. Wages as a percentage of GDP has been hovering around record lows, while the economic conditions following the 07-08 crisis mainly benefit the asset holders rather than the people who rely on wages. As six years after the crisis the economy is still sluggish, is it wise to ignore this part of what made America the greatest country in the world with a robust economy supported by the purchasing power of its middle class?

On the other hand, Finance 101 says that a corporation's main goal is to serve as an agent for the shareholders and represent their best interests, and if the shareholders are interested in immediate profits then the executives must follow suit. In fact, profitable companies can attract investors and in this way promote economic activity. Successful companies can also expand and as a consequence increase the number of people on their payroll. Therefore, perhaps it is best to let market forces govern and trust that in the long run they will dictate what is best for the economy.

In my opinion, sooner or later some action will be required to address the growing inequalities, and kicking the can down the road could make the ultimate solution more costly. I do believe that the companies should reinvigorate their attention to maximizing the benefits of their stakeholders, even if it means higher salaries for the employees and potentially slightly lower profits in the short term. This could boost not only the struggling middle class but also the overall economy as well.

Do you agree with this view? Are the companies right in maximizing shareholders' value, often by focusing on short term goals, while ignoring some of the key stakeholders such as employees? Will this come back and hurt the corporations as the author implies?