The fact that the fantastic has survived through generations and eras, despite a monumental effort to suppress certain forms of it, is astonishing, and leads me to conclude that there must be something in us, something wired into our DNA, that makes mankind susceptible to the whims of the fantastic (we'll call it fanty from now on, just so it can have a cute name like SF does--i.e. sciffy--and if you're really clever you'll catch the Firefly/Serenity reference).
We know this from history: the fantastic is woven into us more finely than a nano-fiber coat (if such a thing exists). The cavemen and other early cultures had some idea what it was, and drew it and exchanged stories about it without realizing that was what they were doing. Numerous religions were founded on the very prospect of the fantastic too, and one cannot deny the relation all religious share to one another, even those religions in existence today. So much of our existence is founded in principles of fantastic discourse as figured through all mediums (fine art, writing, spoken word, etc.). So, is it any wonder that fantasy, as a genre, is doing so well, or that science fiction film (and even fantasy film, for the most part) have such a strong hold on the visual market? The fact that young adults and children gobble this stuff up like so much candy is testament to our human desire for the fantastic; as adults, we may shed some of the "silly" aspects of our youth, but there is always that thread (of course, some of us never grow up, and that thread is still wrapped around us as a coat).
Now, the question is: is it possible to cut ourselves off from the fantastic (assuming we wanted to), and if we did, what would the consequences of that be? Would we lose a part of our souls, or would it be like losing a toe (no big deal at all)?