Once you go beyond these 'legends', to the, I believe, much larger group of people described in the article, this no longer seems to hold, though. The "legends'" possibly inadvertent, yet widely publicized, financial success, seems to have drawn to The Valley many more that ARE in it for the money, and these are the ones I doubt will ever be content.
I would think that having a lot of money would give you the freedom to choose your work, and the ability to wake up every day and work on something you feel passionate about would make you happier. I guess you could say that you don't need a lot of money to do that. But it would make it easier.
I suspect people who work 60 hour workweeks have a tougher time supporting their children (emotionally, not financially), but stay-at-home parents also have trouble setting examples for their kids. It's all a tradeoff.