The culture is the product of many personal decisions. If I was working nights and (especially) weekends at my current employer (another big tech company), I would be told to stop.
Overarching thesis is the people who work to live don’t want to be dragged by those who live to work. Not a judgement about someone’s passion.
Something to remember, especially if you have anyone working under you - your work level will be seen as the minimum for your team members, not the exception.
Generally speaking though, companies should value output and results over hours. Easier said than done. Additionally, value should be placed on what one commits to do and delivers on. So if somebody is constantly having to pull late nights to complete work, they may be overcommitting. It's also possible a manager will consistently push people to overcommit: this is a problem because that can indicate poor boundaries, bad planning, poor resourcing, and so on.
Sure. And if the culture of the company/team is working 40 hours a week max and calling people out when they work more than that, then maybe it isn't the right fit for you.
At the same time I can accept some nuance here, e.g. working nights and weekends because you're taking some time back during the day in the week.
Similarly with remote working, if there's a wide enough timezone difference you might shift your routine to maximise overlap with the team.
I'm strongly in favour of maintaining harmony between work and life such that you're able to comfortably do both, but would not insist on a hard and fast rule.
If someone even further up the ladder says X does nights and weekends, so should the rest of the team, then the buck stops with that person, and they are contributing negatively to the culture.
If not by law, then because almost noone is happy working 60-70h and it puts pressure on others who feel like they also need to work similar hours. Additionally the efficiency gets worse as the weekly hours increase.