Here, I think the post makes clear why they talk about the author like this: some will have heard of Bob Martin for his political opinions, and could well wonder whether the book features them along with technical opinions. This would be a legitimate review topic no matter the political views.
Hacker News has a strong "focus on the tech, not the politics" contingent, so I'd think they'd be especially open to a book review that evaluates whether a technical book did what they were asking for.
When I read a post entitled "A critique of...", I expect an objective analysis of the information provided by the book, not jabs at the author. I hope this is helpful.