I think it is apt to call it insane.
Consider this: it's not uncommon to see people 'working' nearly twice the hours of the Western average. Yet their GDP per capita is comparable if not equivalent to the Western average.
Since most other economic measures (that is, their standard of living) match up with the West, you're forced to ask yourself, 'Are Japanese people half as productive?' Is that why they have to work twice as much? I'll bet against it. It's because they have an insane work culture.