His point is that joining as the 20th employee is often an suboptimal position economically. There's a lot of stability in joining a thriving company that's not

His point is that joining as the 20th employee is often an suboptimal position economically. There's a lot of stability in joining a thriving company that's not going to go bankrupt (e.g, Dropbox). There's a lot of financial upside in being an early employee at a company that becomes successful. Joining as the 20th employee is what Thiel thinks is the worst risk-adjusted financial outcome for an employee -- so what other reasons are you creating for people to join you?