If you were teleported back to the year 0 and went to what is now the US and encountered a large ethnically homogeneous tribe, what exactly would that smoke signal to you?

(Editing: as far as "ascribing what you think", the only things I've ascribed to what you think that you think that ethnic homogeneity in post-European white population is morally improper, which is exceedingly clear from the phrasing of the first comment you posted when you called it a "problem", and that you believe your community was racist, which is clear from the second comment you posted.)