>>96409905
"Grimderp" is often used by people who don't understand how strange things can get.
Real life is crazier than fiction.

40k, especially the imperium, should be WAY weirder and insane than is portrayed.

Problems?
1) It wouldn't appeal to people, picrel
2) Even if they tried most writers are incapable of tapping into that, for the same reason some incredible feats or nightmarish events have to be tone down heavily for people to even consider them possible, despite reality.

TL;DR: people are so retarded that they're holding back fiction.