Because before 1949, life was hell. After 1949, life was better, but still struggle in poverty. Recent years has been the best for Chinese for a couple centuries. People learn to live with what they have and always save money to prepare for a rainy day.

Although, Chinese are willing to spend big bucks on education, especially for their children.

Related to the above, but not really covered in the submitted article, is the 4-2-1 problem. The old model of having your children take care of you when you're elderly breaks down when 4 grandparents have 2 parents who have 1 child.