Musk probably believes he can grow the company into a $100B+ company.
That said the risk is huge as the world can move on quickly as we saw with MySpace. And Elon s becoming increasingly a political risk factor himself in a business were peoples view on the leaders/owners really matters.
His views really don't matter. Nothing happened to Facebook and nothing will. People will just continue fighting (tweeting).
But really who knows. Maybe he realised he had too much on his plate, or any number of things.