As you kind of said, I think people tend to think of work life balance as more of a black and white thing when really there is a lot of grey in the middle. It's a spectrum that many find themselves on either end of. I try to stay in the middle. I have zero problem doing a little more work at home after leaving work for the day, but I don't let it interrupt other areas of my life.
Sometimes more work is required, sometimes less. I think if most people were entrepreneurs, they would realise that being an employee isn't so bad.