2. We Are Very Polite
It is possible that they learned to be so polite with a not-so-polite method. They lived in the days when parents used more than words to teach their children a lesson.
During the time they were raised, courtesy and manners were highly valued. They looked up to people with authority and who were well respected, like teachers, parents, grandparents, and officers. This may have influenced their behavior and communication style.
A lot of them are now grandparents, and they welcome their children, grandchildren, or guests with a lot of joy and never with an empty table. (Our family is our number one priority, and no matter where life takes us, our children and grandchildren will always be more important.)