Indeed... And most of the friends around me who made it big also played it hard.
When Broadcom was nowhere several employees number xxx (with xxx less than 300) were, while in crunch-mode, sleeping in their trucks, on the parking lot, to deliver chip plans on time. Stock options have been good for them the day Broadcom was worth $12bn.
I've got a few friends who started a 3D-rendering business for TV ads, short movies and cartoons. 60 hours a week? Make it 80, 90 and occasionally more than one hundred (you read correctly). I'm talking about people working 15 hours a day, bringing their sleeping bags and pillows at work and eating in a few minutes. They now enjoy 40 employees working for them and have the good life.
I have friends who got money from a business angel and for whom, between angel money and before VC money came, life was work, work and more work.
I could tell you about other people, on the east coast, getting BA money and an office in which they'd sleep (and the girlfriend being surprised to see her new boyfriend living where he works)... And the exit they made selling to a big software company. No 40 hours a week either here but much, much more.
Or another friend setting up a commodity trading (?) company, who's always on the phone and on planes around the world, tracking the ships he's renting and working out deals left and right. Both of us work a lot, yet we find the time to meet (in this or that city in Europe) once in a while.
These people know about burnouts, crunch-mode and... Wealth. Lots of wealth. Yet money wasn't the drive. The drive is simply the desire to achieve great things (build a chip, publish a book, create a company, make an exit, ...).
I've written (and typeset) several books. The last weeks before the book left to go to the editor/publisher were easily 80+ hours a week, working until early in the morning and then taking a few hours of sleep. Rince and repeat. Total crunch-mode. I also know about naps on the bean bag on saturdays and even sundays (!) at Californian startups.
I understand not wanting to work more than 40 hours a week when you're an employee and have a life which you prefer more than your work... But when you're an entrepreneur and want to make a difference, 40 hours a week is nothing.
I'm not saying that there aren't very successful people who've never worked more than 40 hours a week (there are also people who never worked and won the lottery)...
All I'm saying is the entrepreneurs I know who've succeeded big times were (and most still are) relentless workers.
I'm in my forties and I just love what I do. It's saturday, and what did I do? Spent time with my SO, went to buy stuff to paint a room in the appartment, went for a cool drive with my oldtimer and... Spent several hours coding in Clojure..
I even find the time to spend some time on HN ^ ^
You can come with all the studies you want about how 40 hours a week is the limit not to break, unreasonable men will keep being driven by passion and will keep working more than that.
It's not black & white. You want 40 hours a week or, heck, why not 35: try to go to France if you want. Even try to fetch a 4 days out of 5 and you'll be doing 28 hours a week there.
But don't discourage the ones who simply want to work more.
EDIT: fixed a few sentences, not a native english speaker here