I think McCalmont has hold of some valuable ideas about Western capitalist influence, but tends to apply them in an overly rigid fashion-- even if he's one of the people who doesn't know what "literally" means, "our culture is now so utterly wedded to the principles of neoliberal democracy that it has become literally impossible for us to imagine what it might be like not to live under a capitalist system" is pretty silly. You're not necessarily going to see that sort of thing imagined in the SF mainstream, which is regrettable, but I doubt that absolutely no one is doing it. In fact, looking through the comments again, I see people pointing out multiple authors, all recognizable names, who engage with alternatives to capitalism, and McCalmont dismisses them because he has other problems with their work. Fine, but that's irrelevant to the specific issue. The line between discernment and nitpicking becomes an issue again.
Little mistakes like Nigeria/Sudan can be telling. How can one have any faith in his ability to gauge Okorafor's engagement with the real world when he has no idea which specific part of that world she's writing about? It also suggests an inattention that, while understandable if he wasn't enjoying the book, makes him a poor critic of it. (I haven't read it myself, though Okorafor is another entry on my ever-growing list of writers to investigate.)
I hadn't seen until now the absurd distinction between SF and fantasy that he makes in one of those comments where he references Nigeria. If he's really reading SF and fantasy with those assumptions in mind, he's going to project an awful lot onto it that isn't there.