Not accepting external offers to purchase startups is fairly normal. And "we don't like the new overlords" is also a fairly normal reason for refusing said offers.
Fiduciary duty is specifically a moral imperative to do what is best for shareholders. Very often that is a large share valuation!
Sometimes, though, you work for a non-profit (who told their shareholders "we're not actually trying to make you any money, consider your buy in a donation, and your profit to be not being eaten alive by killer robots after AI gains sentience") your fiduciary duty to your shareholders is to continue to not allow an unhinged billionaire who doesn't appear to give two small fucks about any kind of safety to buy your company.
That's what this whole thing is about. Musk's offer will probably not be accepted, and he knows it. The purpose is to throw a wrench in OAI's plan to sell to insiders at a heavy discount, possibly making it impossible for the nonprofit to become a for-profit.
If this offer forces the preferred investments to cough up an extra $60b for the nonprofit, that's fantastic for the nonprofit mission.
