Ken, There is NO implicit criticism of people who don't work nights, and none was intended. Sorry if you came away with that impression.
Google is all about achievement...not which hours you choose to work. The fact is that most employees do not stay for dinner. Google people have different work schedules. Some come in early, some stay late, some work 9 to 5 at the office, and get back online at night after the kids go to bed. Some people work from home. There is no pressure to conform to some schedule.
Google is like a college campus. There are people everywhere, all working different schedules. There is always someone around so you never feel alone.
Don