I can concede that most startups operate as you describe. However, most startups also fail. If you fail in a startup, you can dust yourself off and try again. If you fail in your life, you're going to have a harder time of it.

Maybe it's not best to follow the all-or-nothing strategy that works for startups (or, should I say, that works for the VCs that fund them because they can spread their risk over many investments).