The premise, with an attempt to tie capital-R Rationalists to the neoreactionaries though a sort of guilt by association, is frankly weird: Scott Alexander is well-known among the former to be essentially the only prominent figure that takes the latter seriously—seriously enough, that is, to write a large as-well-stated-as-possible survey[1] followed by a humongous point-by-point refutation[2,3]; whereas the “cult leader” of the rationalists, Yudkowsky, is on the record as despising neoreactionaries to the point of refusing to discuss their views. (As far as recent events, Alexander wrote a scathing review of Yarvin’s involvement in Trumpist politics[4] whose main thrust is that Yarvin has betrayed basically everything he advocated for.)
The story of the book’s conception also severely strains an assumption of good faith[5]: the author, Elizabeth Sandifer, explicitly says it was to a large extent inspired, sourced, and edited by David Gerard, a prominent contributor to RationalWiki and r/SneerClub (the “sneerers” mentioned in TFA) and Wikipedia administrator who after years of edit-warring got topic-banned from editing articles about Scott Alexander (Scott Siskind) for conflict of interest and defamation[6] (including adding links to the book as a source for statements on Wikipedia about links between rationalists and neoreaction). Elizabeth Sandifer herself got banned for doxxing a Wikipedia editor during Gerard's earlier edit war at the time of Manning's gender transition, for which Gerard was also sanctioned[7].
[1] https://slatestarcodex.com/2013/03/03/reactionary-philosophy...
[2] https://slatestarcodex.com/2013/10/20/the-anti-reactionary-f...
[3] https://slatestarcodex.com/2013/10/24/some-preliminary-respo...
[4] https://www.astralcodexten.com/p/moldbug-sold-out
[5] https://www.tracingwoodgrains.com/p/reliable-sources-how-wik...
[6] https://en.wikipedia.org/wiki/Wikipedia:Administrators%27_no...
[7] https://en.wikipedia.org/wiki/Wikipedia:Arbitration/Requests...