The AI text generator could be used to generate fake news or a new generation of spam.
Elon mainly indicated that he needed to spend more time on hard problems at SpaceX and Tesla.
I had to focus on solving a painfully large number of engineering & manufacturing problems at Tesla (especially) & SpaceX
Also, Tesla was competing for some of same people as OpenAI & I didn't agree with some of what OpenAI team wanted to do. Add that all up & it was just better to part ways on good terms.