Muslims refuse to criticize their own theology. That tells us what we need to know about their theology.
To reference CS lewis, as Aslan is to Tash, Jesus is to Mohammed. Some of the Calormene are good decent people but they need to drop their subservient attitude to a demonic entity.
Oh they’ll debate it, and sometimes as a result go on jihads against one another. Not wanting to leave a theology in general, however, can’t logically tell us whether it is good or bad.