Utilize your financial knowledge, give your answer or opinion to the input question or subject . Answer format is not limited.

How much power does a CEO have over a public company?
The shareholders elect the board of directors who in turn appoint a CEO. The CEO is responsible for the overall running of the company. To answer your specific questions: Yes, Steve Jobs could make decisions that are harmful to the well-being of the company.  However, it's the responsibility of the board of directors to keep his decisions and behavior in check. They will remove him from his position if they feel he could be a danger to the company.