Privilege is a major factor in life/work balance. Sure, all of us can learn how to say no, put exercise first, eat healthily, get plenty of rest, and set up date nights. But race, class, sexual orientation/identity, age, ethnicity, etc., play pivotal roles in our options and whether we can exercise them.
I do not mean to imply that only privileged women can live balanced lives. Many do not. But colleagues who are loaded with debt, supporting parents as well as children, dealing with complex commuting arrangements, facing health challenges, and the like simply do not have the same luxury to decide whether they will start their day at the health club or end it with a massage. Achieving life-work balance becomes one more item on an already too long to-do list. For many colleagues survival is the goal.