Probably a reaction to the previous generation. They've seen what happens to people who go head-first into work, watching their marriages and families implode around them, watching them turn into pale, fat slobs who never leave the house, turning into slaves to their bank accounts.
It's likely an over-reaction if anything -- not unlike the current generation of Japanese who are about as anti-consumer as they come after watching their parents blow their wads and collapse in two decades of recession.