Not incomprehensible. People that do it are usually seeking power on earth, they care not about the hereafter or the consequences of such. I think many in power and powerful positions have sold their souls to Satan, especially those that champion blatantly sick, twisted and evil agendas.
I guess that from an evolutionary point of view, satanic beliefs are a kind of encyclopedia of things that don’t work and which are, therefore not fact. How many times do you have to burn your hand on a hot stove to figure, “That’s not a good idea.”