Shahrayar’s madness is a literary representation (and exaggeration) of a universal insecurity. Fear of inadequacy crosses cultural, gender, and age divides. Overreaction to egos being bruised, especially when it involves close relationships, is a common occurrence all over the world. This natural, human reaction is exacerbated by cultural standards placed on men to control the women they are supposed to care for and to never show vulnerability when their feelings are hurt. Those standards are strongest in patriarchal societies, which Shahrayar and the original The Thousand and One Nights audience lived in. His is a special case in that he had the resources to kill so many women in a row, but I don’t believe his reaction was one, especially considering The Thousand and One Nights is a very self-aware work of fiction.
In the Tale of the Ox and the Donkey, there is a special attribute of a human that allows them to be understood. They’re the key element of a morality tale about self-help and confidence in a way that I’m gonna bet modern audiences connect to easier because of a relatively gender-less story. Animals can frequently be written off as effectively genderless in literature. The Tale of the Merchant and His Wife involves animals playing advocates for different societal standards, the Rooster most notably as patriarchal values. These stories’ relatively different roles are more evidence of the varying sources and worldviews that The Thousand and One Nights represents. Part of the reason why this work of literature is so valuable is because it represents, in some ways, a melting pot of the areas it was written and passed down in. Some of those areas are rather progressive (from our point of view) and some others are intensely patriarchal, in which women and animals hold the same role in relation to men- they’re chattel.
Let me answer this by first describing a bell curve. On one end is people who commit no sins, on the other is people who fully and knowingly commit every sin possible; they are the outliers. Most people indulge in a moderate amount of some sins and they lie on the highest point of the curve. The sinless get a spiritual get-out-of-jail-free card. Seems fair enough. But the psychopathic such as mass-murderers and child-molesters, the ones on the other extreme, are lumped together with someone who indulged in one sin and no others. There is no sliding scale, only classifications. This is already not appropriate for the sins committed because it doesn’t take into account severity. This unfairness seems egregious from an objective standpoint.
On a more subjective, personal level, I’ve never felt like harshly punitive measures are effective in the living world. I have no idea why they’re needed in the afterlife. Why not just make those souls go away and let good all go to the same afterlife? What good does punishing anyone do for the people still alive or the people in the good afterlife?