> It's unfortunate that works of great non-fiction writers evaporate away from our cultural consciousness after their death.

That's a bit of an overstatement? There's Confucius, Moses, Jesus, Muhammad, ... Darwin, Newton, Einstein, ... Jefferson, Decartes, .... (you get the idea).

It is a competitive field; what's sufficient to win attention in the current generation is often not enough for future generations, which have their own contemporary writers.