I'm not sure that the author is 100% correct on this point, as it seems to me to be a somewhat blurry and difficult to understand issue (as are many parts of Japanese culture, to me anyway). This "catch-up" mentality could account for part of the reason why so many Japanese people work so much, but there are other, fundamentally linked behavioral patterns that it doesn't explain. And I emphasis "much" because while many Japanese people do work very hard, there is also a tendency to work long hours without actually doing much of substance.
The other behavioral patterns I'm talking about are in fact linked to deference to authority and respect for hierarchy. From what I've heard first-hand, it seems that a lot of Japanese people tend to work less out of a desire to serve the country or be productive than because they feel compelled to. Why? Pressure - both lateral and downward. In many cases, there are certain things that are just expected of you. "Why" doesn't matter. If you go home on time at 5:00, your peers will think you're either lazy or selfish. Lateral pressure.
In Japan, there is something called the sempai-kouhai (先輩後輩) system. Schools, clubs, companies - basically anything with an organizational structure employs it. Essentially it means that senior members (sempai) act as mentors to junior members (kohai). In return, these junior members are expected to treat their mentors with respect and a degree of deference. In other words, if your sempai asks you to come in to work on Saturday to help them finish a project they're working on, you do it. You had a date planned for Saturday? Better reschedule. Downward pressure.
Probably the most common example of this is the Japanese drinking party or 宴会 (enkai).
|Image from: Gourmet Walker Kobe|
In other words, deference to authority and respect for hierarchy are exactly why a lot of Japanese people work as much as they do.
On a more personal level, I think Yoshie's job is pretty good about this. It hasn't seemed (to me anyway) like she's really been pressured to do a lot of work-related "group activities" or work more than she decides she needs to. She does have other kinds of pressure, though. For one thing I think she is pushed to do too much for her customers. But that, perhaps, is a story for another time.