Happy birthday, Daan! Hope you have fun partying tonight.
As to the post, I think Steemit's departure would be catastrophic but not cataclysmic. The blockchain would not completely collapse, but the value would certainly drop hard. Ned's actions are his own, we cannot control him. That said, you'd think he'd want to keep the Steem blockchain (and all its stakeholders) happy and humming right along.
I'm still gonna keep posting though. Just saying...