A God that created all possible worlds would have no moral qualities whatsoever, and could be replaced by a random generator.
One argument based on incompatible properties rests on a definition of God that includes a will, plan or purpose and an existence outside of time.
To say that a being possesses a purpose implies an inclination or tendency to steer events toward some state that does not yet exist.
(In a relativistic universe, presumably this means—at any point in spacetime—time measured from t=0 at the Big Bang or end of inflation.)
A God existing outside of any sort of time could not create anything because creation substitutes one thing for another, or for nothing.