Because they were intolerant and wanted foreigners to be automatically integrated
Things such as religion and other cultures traditions were also spread along the Silk Road Trade routes.
It is possible that in time they could find forgiveness in their hearts for their enemies. They would probably never forget but it is possible to forgive.
The story behind the Trail of Tears. That everywhere they cried on the way, a flower grow.
Evidence would be that child labor laws were put in place since children would work long hours for little pay in very very rough conditions.
