When asked if he regretted not spending more time with his children instead of working, he said quality was more important than quantity, and that the hour and a half to two hours he spent with the children at dinner when he returned home were "lots of fun."
There have been plenty of studies that show working excessive amounts of hours can harm productivity rather than increase it. In Japan, there have been cases of people dying from overwork, leading the country to introduce measures to prevent this practice.