Fantasy is a Marmite®™* genre for many readers: though there is often a middle ground of those who can take or leave it, there are plenty for whom it is anathema and others who regard it as the only true reflection of their hopes, dreams and, occasionally, nightmares. I myself enjoy many manifestations of the genre but not all appeal to me, by any means.
I often wonder what the sticking point might be for those who are anti-fantasy. Not enough realism? Magic too arbitrary or illogical? Aimed mainly at children or the childish? Too full of clichés? Or is there a deeper root that irks the sceptical?
Much of so-called Epic or High Fantasy is predicated on a sense of Fate or Destiny, with prophecies about someone (a Chosen One, if you like) who will bring about changes to a world order. The term Chosen One was used humorously of Harry Potter, but Lyra’s prophesied role in the worlds of His Dark Materials was specifically hidden from her.
But the whole notion of Fate is a controversial one involving whether free will truly exists, or if there is a Being who has their hands on the controls. I don’t intend to get into the philosophy behind the arguments — it’s beyond my wit, let alone my remit here — except to say that bloody wars have been fought over this very issue.