[klempner]

I will remark that, excluding cases where some idiot is offering several times what the company is worth, it is rare that the fiduciary duty issue would force the management of a company to choose unsustainable immediate gains.

The value of a company's equity is based on the net present value of future returns. That means that while short term earnings are important, so are earnings in the moderately distant future. (depending on risk free interest rates)

If a company like Boeing were properly managed, they'd give suitable priority to engineering excellence, at least to the point of not having critical failures like these, because that's core to their ability to compete with Airbus/etc in the future.

The real issue you're concerned about is that it is very difficult to align the interests of corporate managers with the interests of the company. It is relatively easy to align senior management with short term stock prices, but it is difficult for the public to figure out that the gains they see (less engineering cost, faster turnaround time, etc) come at the expense of the longer term viability of the company, so the former gets priced into the short term stock price (and so executive compensation) and the latter does not.