There is some underlying reason for this however. The Economist had an article (can't remember when) about children being accused of being possessed by demons in Africa and either thrown out of the family or village and sometimes being killed. On examination of these incidents by researchers, it was thought that the likely reason was economics and that the parents simply could not feed all the children they had and were dramatically forced to reduce their number. The incantation of evil spirits was simply the rationalisation the parents made to justify their actions.
On two occasions I have seen something similar in the USA. First was in the airport at Atlanta where a early teen girl was having difficulties dealing with the noise and stress of airplane travel. The two women she was with were having an equally hard time dealing with her and were trying to persuade her that the reason she was behaving badly was because The Devil was making her do it. The second occasion was again with an early teen boy but this time at the top of Hart's Pass on the Pacific Crest Trail in the north Cascades. The kid clearly did not want to be there and again the women in charge were dealing with the situation by accusing him of being possessed.
In both cases the kids were stressed out enough to be on the verge of hysteria and the protestations of the adults were only making it worse. It seemed pretty obvious to me at the time that the solution was simply to get everyone to calm down. Doubly so, since becoming a parent I discovered that stress and anxiety are extremely contagious.
So the appeal of demons, for me, is simply a coping mechanism by parents to deal with children they cannot cope with or understand, albeit a a pretty drastic one.