Your 60+ hours per week guy probably doesn't have much of a life outside software engineering. He'd be working between 8,5-12h/day, depending on how many workdays he puts in.
At that level of time investment, he doesn't have time for a romantic relationship. Almost no one would be crazy to accept so little attention, but even if they would it would be a weak & shallow relationship.
They probably don't have time for friendships or even spending time with their family and socialising, which will take its psychological toll.
Unless they magically find time to do some sports and take care not to sit in a chair all time, they're stressing their body a lot, which could lead to a weaker immune system and potentially musculo-skeletal problems.
In conclusion, one can behave like a machine and work 60+ hour weeks, but they're literally trading away their life in order to achieve that.
Get ready to search for a replacement or two for when/if they burn out.
If someone works 12 hour days, and then implements the, and it hurts me to even type it out, "lifestyle hacks" to further squeeze the sponge of productive hours, the sacrifice they make to their own personal lives is a big toll. 12 hour days, plus commute, plus 8 hours of sleep leaves little time for socializing, hobbies and let alone exercise.
But the bigger tragedy is, on a team where there might be competition (eg., a bonus), the guy pissing his life into his work is going to get the accolades and bonuses, or at least it looks that way, which takes a morale toll on the other members of the group. It leads to a race to the bottom.
This might be okay when you're junior, first starting out, or a partner, or someone with significant equity (read: in a few years they won't need to work), but for everyone else, there is a very high risk of a toxic work situation.
To the person above who said that we're highly paid and so forth and expected to perform - well we're not paid because we're expected to perform highly, we're paid because laws supply and demand at present benefit us. If a situation should arise where the balance of the scales reverts, I assure you you'd still be completing your beloved 12 hour days with a much smaller salary.
If it would be just about him getting bigger reward for more work, then it should be fine.
The problem is that people don't socialize at all out of work still have those pesky communication needs. And they use meetings to fulfill them ... slowing everyone down. And what used to be one sentence affair is suddenly 30 minutes long hard to stop chat, because lonely people need to talk. Or one person job is suddenly two person job for no reason other then one of them lack socialization.
And since they dont mind spending there 12 hours a day, they organize things in a way that makes it impossible for other people to come home sooner. Meaning that meetings are late, important information is passed late etc.
And oftentimes means that tired people make more bugs and do less rational decisions. So they insist on work that does not need to be done right away to be done right away for no reason other then fear.
Literally just "not having kids" makes up for the entire extra time and then some.
But really, if you replace things like kids, videogames, netflix, long commutes from the suburbs, spending time with extended families you don't care about, etc, it honestly puts the balance in favor of the person working 60 hours a week.
Now, if they don't ENJOY IT, and they rather be doing those other things, then they should do these other things. Else it is unhealthy, both physically and mentally.
But if I just take my work days + time spent playing videogames + my side projects/blogs/whatever, I come way above 60 hours a week. Sacrifice that and it comes easy.
If it came in the form of additional financial security and it lets you hire someone to clean the house, you might come up even more ahead. The important part is you have to do what you do because you want to.
So the main issue really is that that person will have what other perceive as an unfair advantage, career wise, and THAT's what all of this is all about. People in general are pretty uncomfortable with the idea that someone else is getting ahead of them because they decided to finish that prototype instead of watching Netflix tonight.
While I'm not a fan of 60h per week, I'd disagree here. If you work 12h per day you'll still have several hours in the evening and the whole weekend for your partner.
From my observations, relationships don't depend on how much people work, they depend on how much of their free time both partners like to spend together.
If you're willing to sacrifice other aspects, sure. And if your partner is willing to be secondary to your job, or they have a similar schedule.
Figure 30-60 minutes getting ready in the morning, a 30 minute commute, a 12 hour work day (12.5 with lunch!), a 30 minute commute back, 30 minutes for dinner, and 8 hours of sleep. That's about 22-23 hours of the day. Assuming you spend a grand total of 1-2 hours with your partner, and you do all the things you need to do to be a functioning adult (laundry, dishes, home maintenance if you don't rent, etc) on the weekends.
Or you can work at a company that respects its employees and is close by. From the time I leave my house to the time I come back is less than 9 hours every day, and that includes my commute and 45-60 minutes for lunch (not at my desk).
I am what OP describes. Recently burned out and went on leave for 6 months, and it's happening again two months later. Can't take leave this time, though, since I emptied my savings last time.
The biggest loss wasn't any of what was listed above. No, I knew about the risks and accepted them because I was passionate about creating and contributing. Now the passion is gone. Working and trying to improve causes so much dissonance, like trying to swallow roast beef that always seems to cause food poisoning.
At that level of time investment, he doesn't have time for a romantic relationship. Almost no one would be crazy to accept so little attention, but even if they would it would be a weak & shallow relationship. They probably don't have time for friendships or even spending time with their family and socialising, which will take its psychological toll.
Unless they magically find time to do some sports and take care not to sit in a chair all time, they're stressing their body a lot, which could lead to a weaker immune system and potentially musculo-skeletal problems.
In conclusion, one can behave like a machine and work 60+ hour weeks, but they're literally trading away their life in order to achieve that.
Get ready to search for a replacement or two for when/if they burn out.