No, because shareholders are the owners of the company. The legal requirement is more a fail safe than a mandate, because obviously the company wants to act in the best interest of the company. Without the legal mandate these companies would still almost universally act the same.

There are laws that a plumber can't come into your home and smash up your pipes. That law however is not the thing that prevents the plumber from doing that, the plumber naturally works in your common interest. It's the exact same with companies, shareholders elect a board who hires specialists to run the company. Notice the shareholders are at the top.