The problem didn't start today, it started in the 1980s, when Ronald Reagan was president, and neoliberal economics were first making their mark on policy. Reagan and his ilk distrusted government and believed that the private sector could make the best decisions when left on its own. You've heard about this — it's called laissez faire economics.
This ideology ultimately led to the financialization of the US corporation — the process of putting shareholders first, often at the expense of workers and consumers — and its emergence as an actor that takes resources from the economy rather than creating them. This, combined with a government zeal for lowering taxes rather than spending, means no one — not the government, and not the private sector — is investing enough in America to keep the economy strong across social classes.
In short: Government cuts and changes in how corporations operate mean American workers are getting screwed by their own government and their own employers...
1982 he made it legal for companies to repurchase their shares on the open market pretty much whenever they wanted. Previously, the SEC had considered this a form of stock price manipulation.
This was also the era of the corporate raider, pushing companies to become leaner and more profitable as quickly as possible.
The shareholder became the main thing for a company to worry about. Employees lost their status. Companies feared getting attacked, so they bent over backward to mollify the former at the expense of the latter. Those new stock repurchasing rules, for one thing, allowed them to shore up their defenses by buying back stock. But, of course, that meant spending money that could've gone to innovate, invest in new technology and equipment, or reward workers.