i know you probably know this, but in case anyone has not made the connection, 23andme (and related services) are trying to make real the link between ethnicity and biology which is the fundamental project of (psuedo-)scientific racism. once you have tied ethnicity to a certain set of DNA markers, it is much easier to argue that certain ethnicities are inherently certain traits, which is doing racists work for them.

ethnicity has always been a social and cultural construction with only incidental correlation with biology.