What is the ruling on ill-will and feeling that some legislations, such as the childcare wage, are unjust, and is this kind of thinking considered disbelief (kufr) or a sin?

Allah the Almighty is Wise and Just; He does not wrong His servants. His rulings are based on mercy, wisdom, and benefit, and to assume He is unjust is an act of disbelief. Therefore, the custody wage for the woman is justice and mercy. A divorced woman is not entitled to maintenance after her iddah (definition) (waiting period) except for the custody wage. Likewise, a child remaining with the mother before the age of seven takes into account his welfare and need for affection. After that, the child is given the choice, and the daughter goes to her father. All rulings consider the welfare of the three parties: the father, the mother, and the child. The father does not lose his child by the child remaining with his mother, and visitation is reciprocal between both parties. The custodian may also be someone other than the mother, and she is entitled to a wage for her work. These are some of the apparent wisdoms in Allah's legislation, and He is the Wisest of Rulers, and His law is the most just. As for laws that compel a divorced man to provide maintenance for his divorced wife after the iddah until she remarries or one of them dies, this maintenance is void and not stipulated by the Sharia (definition).