Someone once said they have so many responsibilities as a Mormon that they feel they are doing the worst job at everything they do. I can relate to the "worse job at everything" sentiment - as long as it's kept in perspective. "Finding a balance" implies that something has to give in some or all areas to achieve that balance.
Doing a "worse job at everything" simply means to me that you would do better at each thing if you spent more time doing it. I agree with that completely. If the object of my existence was to find one thing and do it the absolute best way possible, I either would be single or unemployed - agnostic/atheist or a monk - etc. I wouldn't try to "find a balance" - but, rather, I would find my "one true calling in life".
That's not how I view the object of my existence, however. It was made very clear to me early on in my life as a husband and father that my life and the important choices in that life weren't about me anymore. They were about us - my family. That was an important epiphany. My family is my one true calling, and I am fine with that.