I don't read r/badhistory but occasionally r/AskHistorians instead (where why GG&S is bad is literally in the FAQ), and in perusing old threads there, I came across this take that might be interesting to you: https://old.reddit.com/r/AskHistorians/comments/4o1n26/i_wan...

While I think you are probably more likely to sympathize with restricteddata than anthropology_nerd, I do think that anthropology_nerd's comments may be able to elucidate a little bit why GG&S provokes such hostility among academics.