I suspect that most authors don't really want criticism, not even constructive criticism. They want straight-out, unabashed, unashamed, fulsome, informed, naked praise, arriving by the shipload every fifteen minutes or so.
Of course you don't believe in fairies. You're fifteen. You think I believed in fairies at fifteen? Took me until I was at least a hundred and forty. Hundred and fifty, maybe. Anyway, he wasn't a fairy. He was a librarian. All right?