Re Stability AI: Why bother selling 15% for $100?

Apparently Cyrus was unaware of the AI art technology but why bother selling shares if you're only going to get $100? Why not walk away and keep them in case something happens?

"Cyrus Hodes is a tech entrepreneur and co-founder of Stability AI, known for its AI image generator Stable Diffusion. Hodes co-founded the company with CEO Emad Mostaque in 2020. He alleges that Mostaque deceived him into selling his 15% stake in Stability AI for $100, just months before the company reached a valuation of $1 billion, which would have made his shares worth over half a billion dollars."