> and public companies have a fiduciary duty to maximize shareholder value.

Public companies have a fiduciary duty to act in the best interests of its shareholders, maximising shareholder value doesn't mean "in the short term by handicapping long term health" as we currently live under from the management/financial class (and capital investors). The concept has been bastardised, i.e. Boeing's management acting the way they did the past decades has not maximised shareholder value, it has extracted value at the cost of the best interests for shareholders in the long term.

Unfortunately there's no easy way to curtail this behaviour that I can see. Even more when everyone's retirement plan requires being part of the financial market game...

As you mentioned, the incentives are not there for actual maximising shareholder value on the long term, we now see these cycles of healthy growing companies being captured by the financial market when going public, after that it's a process of extracting value in detriment of the health of the company long term, sometimes this process is accelerated, sometimes it makes the company languish for decades, and sometimes the company becomes something else that is still profitable but "evil" in most moral frameworks.