> The stock market mechanism then guarantees that companies unconcerned with that sort of profit will see someone gobble up the shares once they dip low enough (and they will), install a new board of directors, and dismantle the company for parts or some other endeavor-ending inevitability.

There are all sorts of ways to defend against a hostile takeover like this. I already mentioned Zuckerberg having majority control of the voting shares despite the company being public. There was also the attempted takeover of Netflix a decade ago that was prevented with a poison pill to issue more shares.