That's why there are no characters with any depth, except the occasional Mary Sue, that's why the racism and that's why the evolution of the style and philosophy. And because the tales follow the evolution of his character, you don't necessarily get the same angle each time but you can see a development from tale to tale without an attempt to dump the whole kit and kaboodle in one.
I'm not sure why it hadn't dawned on me before.
So, I guess if you want to write some equally compelling horror fiction, look into yourself for your own misanthropic, nihilistic or distasteful traits or philosophies. To thine own self be true.
But if you want to have some nice pickles to go with any meat, to thine own shelf, beetroot.