Employees aren't going to have the same motivation unless they get the same rewards. I've always thought it was absurd when execs would come in super pissed off that everyone wasn't pulling super long hours to ensure that the exec got his bonus. That's nice that you get a bonus Mr. Executive, but your workforce doesn't exist to sell its life away for your special benefit.
I agree with the parent. It is very important that everyone get some time off. I would be hesitant to work for anyone that was so overt about not valuing a proper work-life balance. My applications to multiple startups, including YC startups, have been stopped because they say things like "Make this the most important thing in your life."
My job / money will never be the most important thing in my life. Most important in my life is my family and nothing is going to supplant that. If you make like you aren't going to be OK with that, it's an instant deal-breaker and I'd be reluctant to continue talking to anyone that advocates such a bad situation.
We all like computers and we're all excited to build useful things, but give me a break; anyone who cares more about their startup than the general well-being of himself or his family, which well-being includes proper work-life balance, is severely misguided.
I just talked to a friend who told me who distraught he is that he spent almost every waking hour of the last two years working. He told me he felt like 23 and 24 were empty years filled with nothingness. Yes, he made a lot of money working so much, but it wasn't worth it. It never really is.