It's also a inability to accept the cthullian horror built into nature.

Sentient eating sentient, everything being at constant warfare with everything else- the Grass wars the trees for the light. Add to that, the likelihood that nature will adapt new defenses in our lifetime, by for example having animals propagate hyper-allergenic plant-species - and you can begin to grasp why humanity does not want to look at the real, rather at the idyllic paintings we made ourselves.