>Yes, because it's not an argument the letter is making.

It literally is though. The full quote from the Buzzfeed piece is:

  Reich’s claim that we need to prepare for genetic evidence of racial differences in behavior or health ignores the trajectory of modern genetics. For several decades billions of dollars have been spent trying to find such differences. The result has been a preponderance of negative findings despite intrepid efforts to collect DNA data on millions of individuals in the hope of finding even the tiniest signals of difference.

  But his skillfulness with ancient and contemporary DNA should not be confused with a mastery of the cultural, political, and biological meanings of human groups.

>When he says things like: But as a geneticist I also know that it is simply no longer possible to ignore average genetic differences among “races.”

Note that he put "races" in quotes. The point he was making here is that sometimes genetic ancestries can intersect quite well with traditional notions of "race" [0]. But often times they do not, especially in the case of admixed populations [1].

[0] https://www.nature.com/articles/s41598-023-32325-w/figures/1

[1] https://link.springer.com/article/10.1186/s12859-019-2680-1/...

    Note that he put "races" in quotes.