Total evil is attracted to and relates to a somewhat lesser evil, which in turn is attracted to and relates to evil of an even lesser intensity, and so forth.
But should one layer be removed, the entire structure will be in danger of collapse.
For instance, thieves can flourish only when middlemen exist to sell their stolen goods.
There can be a black market only when there are gray areas in which money is laundered.
If those intermediate areas were eliminated, if all commerce between the underworld and the world of legitimate social and commercial intercourse would be blocked, the underworld could no longer continue to exist.
–Rabbi Adin Steinsaltz