Why this kolaveri di on Indian genetics

I perused through the article linked in Razib’s previous post. I stumbled on this caption embedded in the beginning of the article:

NOT THE SAME: The Indus Valley people lacked the steppe and ancestry that marks many North Indian high castes today (Photograph by Bandeep Singh, for representational purpose only)
I find the association that the prototypical Indian is a high-caste Hindu to be in poor taste.