Have you considered that maybe their work is their hobby, and a huge part of their life and purpose?
I work somewhere where a lot of my coworkers and management are incredibly dedicated and passionate about what we do. They will show up and go apeshit on a project for 12+ hours a day for a month at a time because they're excited about the challenge and the outcomes. Even when they're not working on such a schedule, they often go home and work on personal projects that parallel what they do in their work. There are plenty of days where I can't wait to get to work; all issues outside of it take the backseat. No matter how bad those issues are, I have no choice but to get over them, because my work is never finished.
I'd imagine that some jobs would be grating, but there's a lot of them that would never get old for some people.
I work somewhere where a lot of my coworkers and management are incredibly dedicated and passionate about what we do. They will show up and go apeshit on a project for 12+ hours a day for a month at a time because they're excited about the challenge and the outcomes. Even when they're not working on such a schedule, they often go home and work on personal projects that parallel what they do in their work. There are plenty of days where I can't wait to get to work; all issues outside of it take the backseat. No matter how bad those issues are, I have no choice but to get over them, because my work is never finished.
I'd imagine that some jobs would be grating, but there's a lot of them that would never get old for some people.