That's a sweeping and unqualified statement. I'm very happy as employee #1 at a very early-stage startup. I'm learning more, and faster, here than I could hope to anywhere else. And not just engineering know-how. I'm getting a de-facto business-school education. On top of it all, I'm having a lot of fun.

The risk is "maybe didn't maximize earnings over n years". The reward, regardless of the startup's success is "learned a lot, enjoyed myself a lot". That's reward I get no matter what.

EDIT: Additionally, I applied in the fashion of #3 (from the article).