Mere longevity is a good thing for those who watch Life from the side lines. For those who play the game, an hour may be a year, a single day's work an achievement for eternity. ↗
Working long hours being single helps because your time is yours. Once you have a family your time isn't all yours anymore. Most of the Mac team, we were in our mid-20's, most of us were single, and we were able to essentially devote our lives to it. ↗