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.