Remember why you dropped out of engineering school and decided you had a call for the ministry? Comparative religion, homiletics, higher criticism, apologetics, Hebrew, Latin, Greek, all require scholarship... but the slipstick subjects require brains.-Robert Heinlein, Job: A Comedy of Justice
Thought of doing a careful point-by-point refutation, but ehh. At around the same time that the Mieville talk came through the feeds, I got this video from PHD Comics on "The Fingerprints of Stars."
Mieville's a scholar of sf and fantasy criticism; what about the famous "sense of wonder?" What about "Big Dumb Objects?" Consider the stars, indeed. There they are, in every way, on every level, bigger and more awesome than all of fantasy put together; oliphaunts, fastitocalons, Dark Lords, Elder Gods, and all the rest.
Once we overcome our fear of being tiny, we find ourselves on the threshold of a vast and awesome Universe that utterly dwarfs — in time, in space, and in potential — the tidy anthropocentric proscenium of our ancestors.-Carl Sagan, Pale Blue Dot
Of course the thing about the endless debate on sf and fantasy is that they're fuzzy sets: hard sf (Greg Egan, Peter Watts, etc) is the conceptual anchor, the core whose gravitic pull defines sf, and distantly influences the science fantasy middle ground (Star Wars, John Carter, etc). A good heuristic is that fantasy is system 1, or default mode, where feelings are primary tools of judgement, and evil is defined by a sense of wrongness. While (hard) sf is system 2, or task positive, requires cognitive effort to keep up.