Translating "best interest" to "maximize profits" is the stretch though. The shareholders define what is their best interest. Shareholders aren't faceless demons. They are you and me.
The main interest of a shareholder is return on investment. And that's fine. The problem is that if you don't have enough competing entities in a market, these shareholders of the few companies that still exist hold disproportionate power that can and will be misused to make any attempt at new, reasonable competition infeasible.
It's really not that hard to understand.
No, it's not fine. Legally, maybe, but not morally fine. I don't understand how everyone is ok with this system which seems to be selecting for the worst humans.
Wait. If you invest your money into something, do you not expect a return?
These are not people, they don’t think morally the way people do. These are not demons, they are not evil themselves - these are more like machines, algorithms tuned to maximize profit. This structure is our paper-clip optimiser, already in place much before the AI revolution. If there is a devil, they are the ones behind setting up this entire system, not a player in it.
ensuring the system does not degenerate is the job of regulators.
Of course, regulation is needed to stop a bad board.
Your couple Tesla shares doesn’t make you a “shareholder” as being discussed here. The shareholders that sue boards are shareholders who, if they sold, would disrupt share price notably.