What's missing from this is that Google's culture is designed to eliminate work-life balance by making as much of life as possible focus around work. A significant part of the compensation for Google employees is in the form of good "free" meals (including dinners), lots of services, entertainment, etc., all without leaving the Google campus. Would be interesting to see how the results are different from similar surveys done at a company like Microsoft that doesn't have such an all-encompassing work environment.