There are rewards, and naturally, there are punishments!
Demon Cultivators, who produced and widely spread the black filth, all tainted themselves with Karmic Force, the only difference being the extent.
If merits are synonymous with beauty, then Karmic Force is its exact opposite, carrying it makes one despised by the Heavenly Dao and shunned by the world.
Even the unconstrained Demon Cultivators, who slaughter mortals and kill Cultivators using various evil materials for Cultivation and refining Spiritual Objects, would not incur Karmic Force as long as they do not disrupt the natural order!
As they say, "Heaven and Earth are heartless, treating all creatures as disposable."
To put it bluntly, the Heavenly Dao is not benevolent and treats all beings as lifeless offerings.
And the punishment for this by the Heavenly Dao is far beyond just these!
The most severe is the reduction of Demonic Tao's Qi Fortune by the Heavenly Dao by a whole ten percent!