That's true. Rings and accretions are sure to form. But what I want to know is that why the plane is vertical to the rotation axis? Can it not be vertical?
Why the plane of the rings is vertical to the rotation axis of Saturn?
I don't think this is a coincidence, because the orbits of the 8 planets in our Solar System is roughly in a plane, and some galaxies are like a plate, so does the accretion plane of the black hole. But as we know...