Japanese elderly survived the horror of the war then had to go through reconstruction, same happened in Europe too.

Americans had seen the horror of war but the homeland was never affected, this enabled the boomers to be raised in an environment where they were valued a lot as a future after a VERY bleak past and present but unlike Asia and Europe, none of the restrictions of rebuilding a whole country. This meant they grew up thinking they could have it all which led to the current state of affairs.