I think being dogmatic in these circumstances is perhaps a little short-sighted. As with all things, finding the middle ground – balance – ought to be the goal, and not rigid conformity to rules. In this circumstance, it sounds like you'd might be hard to work with.
That being said, an employee with balance and boundaries, particularly if they can be seen in your life outside of work, is far more desirable in an employee than someone with none. How we live our lives outside the work place is indicative of how we function inside the office, and setting boundaries around the office shows a healthy valuing of our personal time.