Yeah, no, bad writer, great writing. I never realized how immensely quotable and eloquent short excerpts of his works are, until I looked up those specific quotes.

If the sculptured maps and pictures in that pre-human city had told truly, these cryptic violet mountains could not be much less than 300 miles away; yet none the less sharply did their dim elfin essence jut above that remote and snowy rim, like the serrated edge of a monstrous alien planet about to rise into unaccustomed heavens. Their height, then, must have been tremendous beyond all known comparison—carrying them up into tenuous atmospheric strata peopled by such gaseous wraiths as rash flyers have barely lived to whisper of after unexplainable falls. Looking at them, I thought nervously of certain sculptured hints of what the great bygone river had washed down into the city from their accursed slopes—and wondered how much sense and how much folly had lain in the fears of those Old Ones who carved them so reticently.

The language is just… sublime, his vocabulary is such a vast vessel that I - as a non-native speaker - am happy enough to understand when read but will likely never be able to command myself.