You're still not getting it. Management only "needs" to answer to shareholders. Shareholders are effectively "the owners". Saying management has a legal responsibility to pay its employees is based on a contract between two parties. It doesn't mean either the employees or the customers have any (legal) "right" to tell management how they should operate the company or how to conduct its policies.
The primary responsibility to shareholders is that executives may not enrich themselves at the expense of shareholders.
That is not the responsibility of the shareholders; that is the shareholders' prerogative. A shareholder can only try to influence policy within a company, or divest themselves from the company. Should management get involved in criminal activity, that is not the "responsibility" of the shareholder to "prosecute" or "punish" management for it. Shareholders only receive financial loss from such corporate malfeasance.
A company has a responsibility to treat employees with dignity and respect.
No, they don't. Its not responsibility, its common sense only to the extent there is a clear understanding between management and employee of policy. What's "good business" is not the same thing as "responsibility". One can make the claim "Trying to hire H1-Bs over a native worker is not treating the native worker with dignity and respect", but that doesn't mean the company has a legal responsibility to hire the native worker over the H1-B.
Another sad aspect of this is the Chick-Fil-A episode with its "attitudes" towards homosexuality. There is no legal requirement that Chick-Fil-A show "respect" to homosexuality towards its customers or employees. When some gay customers, employees, and neither tried to organize a boycott towards Chick-Fil-A, it had the negative result of rewarding Chick-Fil-A's behavior by its customer base, who apparently either semi-actively prefer Chick-Fil-A's behavior towards homosexuality or feel the homosexual community overstepped in imposing their prerogatives (lets call it "respect") upon the company.
Communism or "American Liberal" sense of "decency" has no business in dictating to a company in a capitalist economy.