Earlier quoted context omitted.
Both of those are true, but part of learning how to make your own choices is learning how to ignore the choices of those around you and adapt to (but not be defined by!) the circumstances you find yourself in.
But adapting to circumstances includes adapting working hours. If companies expect 80 hours a week, you will be fired or have too low salary no matter how great your output is. Then you have to move if you do not want to work those 80 and be employed/work on interesting projects.
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.