I undoubtedly will regret this later, but I must throw in my "two cents" here.
Let us not forget, the Nay Science was published by a highly reputable press (OUP). Of course, that does not mean that the book should then not be judged on its own merits. But, having said this, I happen to have read the book cover to cover (and read it quite carefully, having an upcoming review of the work). Not unlike any scholarly work, it has its merits and its demerits, but the important point here is that it decidedly is a work of scholarship (and, again, I cite its publication history). Works of scholarship justly invite discussion. Indeed, having actually read the work, I consider the polemical nature of the Nay Science to be among its strongest elements. Agree or disagree with the authors contentions, their work invites serious reflection, both on the nature of Indological scholarship as well as on the nature of the humanities in general (this critique emerges in the final chapters of the Nay Science).
I, for one, am grateful for the authors' boldness and for their willingness to continue challenging "received" wisdom. And, yes, such challenges do at times fairly engage issues of personal identity (Jewish; German; Indian) insofar as these issues emerge in an individual's scholarship. But to engage them as a matter of "race" is as undignified as it is illegitimate.