No, the implication being that insane and decadent rulers were a standard feature of Muslim Absolute Imperial Autocracy. Which kind of is what the entire system of decadence is all about anyway.
Islam is based on a very strict and clearly established set of laws, because there is no separation of state and church, unlike the other European religions of the time period. Arbitrary dictature was more common in the European mindset, it was "normal". In Islam, the big autocratic dictators ignoring the Quran were indeed batshit crazy most of the time. The second Caliph even believed that Allah actually took example from him.
So no, the implication isn't that every Muzz leader is crazy, just that the absolute ones were.