Nailed it!
Last year when the book came out, Pharyngula atheism/science blogger PZ Myers linked to a vlog post about it by Rebecca Watson (Skepchick).
You seem to be a bit mixed up about what an ad hominem argument is. It’s when somebody references the personal characteristics of an adversary in order to discredit their position on an unrelated subject.
That’s not the situation here. The ideological alliances formed by a scientific public figure of, to say the very least, extremely questionable personal ethics are entirely relevant to his editorship of a book that’s all about ethics and ideology in the practice of science.
Rebecca Watson is an excellent and funny source for anyone who wants to be informed on the comings and goings of the anti-woke, right-wing, grifter community.
It was Dawkins obsessive hatred of her retelling how inapropriate it was for an unnamed Skeptic member to sexually proposition himself to her when she was trapped in an elevator with him (at a convention many years ago), that firmly made me break all respect with Dawkins. PZ Myers had a similar reaction at the turning of the septic community too (if I remember correctly). Won a lot of respect from me there.
Same, although LOL “septic” typo 
Yes, opinions on the BOOK, not the personal problems the author has.
Like I said upthread, in this case the author’s “personal problems” regarding ethics and ideology are extremely relevant to his editorship of a book addressing the subject of ethics and ideology in the practice of science.
If someone were dunking on Krauss’s book because he’s balding or wears glasses or something like that, that would be a fallacious ad hominem attack that you’d be right to criticize. But pointing out his ideological embrace of “the right wing pipeline” once he was widely discredited as a public figure due to his abuse of his academic position and his apologetics for sleazy criminals such as Epstein? Entirely appropriate in the context of his shilling for an anti-“woke” propaganda whinefest and claiming it’s some kind of defense of “science”.
Nothing wrong with reading a book that treats “DEI programs, wokeness, and cancel culture” as big-time threats to science.
But it seems at the very least quaint to focus on those issues, in the face of massive recent government cutbacks to research funding, nomination of cranks to oversee public health policy and ideologically motivated government officials pressuring scientific journals over their retractions of methodologically poor, deeply flawed articles, while administration hacks block publication of research validating effectiveness of Covid vaccines.