Our choices are often informed, for better or worse, by those around us.
And, for those for whom compensation is attached directly to how many hours they spend working (when you think about it, this group includes plenty of people on "salary" as well), where you live and the hours you work are directly correlated.
Different places have different cultures. I'm not going to go so far as to say that Israel's work culture is more relaxed than the valley's, because people work their asses off here, too, but I think there's definitely a more "chilled" attitude here. As an example, most people go to the army for at least 2-3 years, then take 6-12 months off to explore the world before getting their bachelor's degree (which takes 4-5 years). How many people in the valley have this kind of lax attitude? In fact, most of the valley's prized examples can't even wait to finish their freshman year of college... see the difference?
I also think the fact that most people are a little older and have a little more perspective (having served a minimum of 3 years defending their country) changes the dynamic. Just my opinions.
I live in Silicon Valley, and I work for a company that's somewhat famous for getting its employees to stay on campus all the time. I usually work 6-8 hour days, and occasionally put in some time on the weekends but usually go have a life instead. I'm leading a very high-priority company project, and I get paid...generously. I don't expect my team members to work any particular hours; hell, I'm terrible at keeping set hours myself. I do expect them (and myself) to make solid progress toward the goal every day, to seek out information and make smart decisions, and to focus their efforts on areas that other people are not already covering.
There's often a lot of leeway between what people say they want and what they actually want. Discovering that leeway is the art of negotiation, which is a useful skill in its own right. If the culture says it wants 80 hour weeks, it does not necessarily mean your employer wants 80 hour weeks. Most likely it wants rapid, dependable progress toward a goal, which is usually better obtained with solid 40-50 hour weeks.