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).
Some startups will be worth it (eg: Google, Facebook), but if you average them all, the risk/reward ratio is not worth it in general. There are a lot of crap startup out there, and you only have so many years.
Also, if you are a VC or a co-founder, then the risk/rewards ratio totally changes, and it's most definitely worth it. But if you are like the rest of us, then it's a big NO.
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).