I think his argument is basically right: fiction that treats of kings and queens without any kind of satire, irony or other form of undermining is implicitly endorsing conservative and authoritarian ideas.
Which made me go, mostly, "oh goodness, not again" (as this stuff has plagued my childhood from dinner table shouting matches to the ban on Spinrad's "Iron Dream") and then steaming over it on low flame for quite a while, until I came to two ideas which I might find useful dealing with that in the future:
#1: Creating a narrator's voice that makes the most weird, strange, outdated or plain creepy things sound completely logical and common sense is half the fun of writing. It is, in fact, so much fun that if you succeed in it, it's worth being called a sick, perverted, crypto-commie-fascist anarcho-authoritarian. (Only remember to use a pseudonym when you do it.)
#2: Author's assumptions show themselves in the way their world works, not in the narrator's voice. This goes into degrees of realism and I don't have the patience (oh, look, a Schlumbergera, I have one just like it at home!) to define this in any useful sense, but I think most readers have encountered the effect that it's easier to suspend disbelief in magic than to suspend disbelief in genetics. Or something similar.