And if you love doing something, you'll certainly love it more if you do it 24/7! The world isn't this black and white.
Some people are sprinters, and some are marathon runners, and even more people are some combination of the two at different points in their lives. Sure, some jobs require people who can sprint for 12 hours a day, 6 days a week, with litte vacation, but many people don't want to live that way...
If you hate your job, you won't love it by reducing the hours, but it might make it more bearable. If you like/love your job, but it's pushing you a bit too hard, you may find it even more rewarding if you reduce your hours.
Some people are sprinters, and some are marathon runners, and even more people are some combination of the two at different points in their lives. Sure, some jobs require people who can sprint for 12 hours a day, 6 days a week, with litte vacation, but many people don't want to live that way...
If you hate your job, you won't love it by reducing the hours, but it might make it more bearable. If you like/love your job, but it's pushing you a bit too hard, you may find it even more rewarding if you reduce your hours.