"There seems to be a basic element of horror in most things", has been written elsewhere.
I call that the Ominous Imagination. We need a neo-ominous one, perhaps! As to gross-out horror impeding the growth of the horror arts in general, that's partly true, but also how art-mediators package it. Extreme Horror in an art museum is just another way to package it. Blatant jagged noises played as music, yet another.
There are not so much individual prejudices against various forms of art or music or writing, but a mass anti-hysteria where we all follow mutely the pattern-trails laid for us by coordinated paper chasers who *do* have individual prejudices.