It's not a misunderstanding its how companies work. If you make shareholders unhappy you simply risk them leaving. Thats why on average companies do things that make them happy. Oh, also the shareholders pick the board and the board does things for the company. You can see the relationship now?
I know how companies are governed, and it is of course an empirical fact that most large listed American companies are run to maximise stockholder value. But that does not mean that it is the purpose of all, or even most companies. People run companies with a variety of reasons, including things like having fun or making the world a better place. More importantly, companies have moral obligations not only to stock holders, but to the employees, the environment, and the communities they operate in.
You're right - that is a misunderstanding. I think you accidentally replied to the wrong comment seeing as I didn't say or imply that.