What is the reason that something disliked (makruh) is disliked and not forbidden (haram), and why did Allah not forbid it if He dislikes it? And does the same logic apply to other disliked things (makruhat), as is the case with divorce in the weak hadith: "Indeed, the most disliked permissible thing to Allah is divorce"?

In the terminology of the Usuliyyun (jurists specializing in the principles of Islamic jurisprudence), makruh (definition) (disliked/reprehensible) refers to that which is prohibited in a non-binding manner. الفقهاء (jurists) may sometimes use the term karahah (dislike/reprehensibility) to mean tahrim (prohibition), or nahy al-tanzihi (prohibition that is not strictly binding but rather cautionary), or that which is better left undone. There is no contradiction in establishing karahah with this meaning; it is similar to mandub (recommended). Evils vary in their degree, and thus it is appropriate for rulings to differ. Evils are of two types: that which Allah has forbidden approaching, and that which Allah has disliked committing. This is what Al-Izz ibn Abd al-Salam clarified. The Hadith (definition): "The most detested of lawful things to Allah is divorce," indicates that divorce is permissible and not forbidden. It also shows that among lawful things, there are some that are disliked by Allah, and the most disliked among them is divorce. There is no reward in it, nor is it a means of drawing closer to Allah.