Why wouldn’t they think so, when most of the crimes that get reported involve people of color, such as the homicide rate in Chicago?
But it also partakes of the tendency of many Americans to assume other nationalities are inferior to us. How many times have you heard how foreigners “still” think America is the greatest country on earth? (Debatable at this point, for sure.) When soldiers came back from Europe at the end of World War II many of them disparaged Italians (“how many speeds does an Italian tank have,” “they would sell their own sister,” etc.) without apparently considering for one minute that they had just witnessed a society on its knees.