Actually I'd like to revise my opinion a bit because I'm hydrated now and my friend in chat pointed out that my "inhumanity of form" and "recognition of personhood" are just two of the MANY axes upon which the monsterfuckerness of anything can be judged, so I propose this:
Kink in general, but ESPECIALLY monsterfucking, is the exploration of what could be. Playing Imagination, if you will. Therefore, it's opposite is a total lack of imagination.
Since it's extremely weird for a human to be totally without creativity, what you get is a bimodal distribution on either side with a sharp dip in the middle, where the vast majority of people are into something A Little Weird, tapering out the Spiders Georgs out there who want to be actually jacked off by the invisible hand of the marketplace or suchlike esoteric and unachievable fantasies.
Hence, wanting to fuck a vampire is both monsterfucking and normie at the same time.