This is a myth.
https://skeptics.stackexchange.com/questions/8146/are-u-s-co...
This is a myth.
https://skeptics.stackexchange.com/questions/8146/are-u-s-co...
https://www.professorbainbridge.com/professorbainbridgecom/2...
“The court may hold forth on the primacy of shareholder interests, or may hold forth on the importance of socially responsible conduct, but ultimately it does not matter. Under either approach, directors who consider nonshareholder interests in making corporate decisions, like directors who do not, will be insulated from liability by the business judgment rule.[9]”
This thread https://news.ycombinator.com/item?id=23393674 has a lot of quotes from primary sources and legal analysis, and reaches a similar conclusion: directors can largely do as they please.
Acting in shareholders interest is not strictly equal to optimizing shareholder returns.
However this does not need to be the case. If the owners/shareholders want they can demand the company to be responsible for the environment, to be socially responsible as well, or to do basic research instead of maximising short term profits. It just requires the majority of shareholders to want that, and right now this still isn't the case.
This is actually something I picked up from reading Milton Friedman's books, where a corporation exists to do the will of the owners/shareholders. Maybe I read it wrong but that's what I understood it as.
"If the legal obligation to maximize profit for shareholders existed we would have to develop a good definition of how is is to be measured."
Translation of this bad argument: "Everyone uses words differently, so laws are impossible."
We have almost a century of stockholder lawsuits, some successful, to show how ridiculous this argument is.