He was referenced, because of another article (see link in my post) on work-life balance.
What do you mean by "balance" if you don't mean the normal definition of "engages in activities/pursuits from all aspects of life"? By the normal definition of balance Elon Musk is not leading a balanced life at all, but a dedicated and focused life. This is not a value judgement, it's perfectly reasonable to make that choice.
This idea that balance is different for everyone makes me think you are using balance to mean "fulfilling" or "happy"?