This doesn't seem true. What about having voting rights on board members/company direction? How do worker-owned co-ops even function if this is the 'whole point of owning part of a company'. Why do we take 'maximize shareholder value' as though it's some rule handed down by god and the only possible way to operate a company, public or otherwise? It just isn't the case.
You don’t just control a company for fun. I mean, maybe you do and more power to you, but just about everyone else votes in those elections so that the company will be better run, so that in the short/medium/long-run dividends or share price will go up.