In relation to other comments here. There is "coding" and there is "God's spark genius of algorithms" kind of work. This is what made the magic of OpenAI. Believe me, those guys were not "just coding". My bet is that it could be all about some research directions that were "shielded" by Sam.
I really don't buy that for a second. Most of OpenAI's value compared to any competitor comes from the money they spent hiring humans to trawl through training data.
In short, either they didn't or where unable to create a favorable enough environment for this to flourish.