Mozilla has this same structure (non-profit parent, for-profit subsidiary) because the subsidiary has to pay taxes on the money Google pays to be Firefox's default search engine.
As do many gift shops attached to non-profit museums and art galleries.
The difference is that Mozilla’s for-profit arm is owned by the non-profit. The for-profit part of OpenAI is there to make a lot of individuals and for-profit corporations rich.
OpenAI’s profit-generating subsidiary isn’t just there to further the non-profit mission like a museum gift shop or Mozilla’s for-profit subsidiary.
That’s why this was scrutinized more and the California AG got involved but it’s not that rare either.
Novo Nordisk the maker of Ozempic for example IPOd, diluting the Novo Nordisk Foundation’s share (though they still have controlling voting rights due to share classes IIRC) to raise money. SRI International spinoffs often get sold (Siri) or raise money and IPO (Nuance) diluting the nonprofit’s share significantly in the process.
A nonprofit that owns a for profit subsidiary is no different than a regular shareholder and can decide that diluting to reward employees or get investors is worth it to grow the value of the whole company.
OpenAI - the AGI entity with a gift shop.