Regardless of where AI currently is and where it is going, you don't simply quit as CTO of the company that is leading the space by far in terms of technology, products, funding, revenue, popularity, adoption and just about everything else. She was fired, plain and simple.
Or you are disgusted and leave. Are there things more important than money? You'd certainly be certain the OpenAI founders sold themselves as, not'in'it'for'the money.