Moreover, CEO is legally obliged to work in the interests of shareholders. That is the law, and that is one of many reasons why corporation flourish in the US: you can buy stocks and be protected from management deciding to waste money listening to each immature employee.
It still seems pretty evident that the power structure at larger companies necessitates that people do act in the interest of investors - as doing so is in their own best interest. I'm no expect and I'm sure more educated people could argue both sides of that though. In the end, I think the behavior of companies that exist is at the very least enough to suggest that the organization of companies in capitalism motivates profit above all else - to the point where horrible acts are committed frequently and are expected from larger corporations
For example, they could provide bonuses for making environmental improvements such as reducing pollution, or they could withhold them if the company gets in trouble for exploitation or criminal activity.
Yeah, that's why investors invest, but you (like many people) are forgetting that society allows companies to exist in the first place: to provide social value and increase the general welfare. That's not measured in how much money a company makes for its investors.
If an employee finds themselves working for a company that's hurting society, their primary duty is to stop that harm, not to be circumspect of the investor's profits.