Just because you donate money doesn’t mean the charity or nonprofit (or whatever OpenAi is), can do as they like. They may still be committing fraud if they are not using the money in the way that they claim.
(Not a lawyer, obviously.)
As for lawsuit vs criminal prosecution, the waters there are somewhat muddied. Consider the OJ case, where he was acquitted in the criminal trial and then found liable in the civil trial. Really bizarre stuff.
Personally I do think more things should be pursued criminally, but instead we seem to just be content to trade money through the courts, like an exorbitant and agonizing form of weregild.