The American landscape is littered with many large companies which have gone bankrupt by giving in to all their employees' demands at the cost of profitability. The big airlines, for instance. And the carmakers.
That would seem to violate everything we know about public relations, i.e. it's a whole lot easier to get your voice heard when you have money.
The fact that you don't hear about it is, rather, because shareholders have voting rights to control important decisions, including board selection, and the board supervises management, as well as corporations having legally-enforceable fiduciary duties to shareholders.
So, if a company is not adequately representing shareholder interests, they have more efficient mechanisms available to correct that than "whining to the media", as a result of which, management is generally responsive to demands that come from a substantial fraction of the shareholders in ways which they may not be to employee demands.
This depends upon the state. In Delaware corporations, directors and officers owe fiduciary duties to the corporation and shareholders. See Buttonwood Tree Value Partners LP v. R.L. Polk & Co., C.A. No. 9250-VCL. The difference might seem moot to laypeople, but is incredibly important for those real people acting as officers and directors who are directly involved in corporate governance activities.