Did you actually read the essay?

In Aristotle's Metaphysics, he suggested the need for an "unmoved mover" to explain the motion of ordinary objects. That makes sense in the context of Aristotle's physics, which was fundamentally teleological: objects tended toward their natural place, which is where they wanted to stay. How, then, to account for all the motion we find everywhere around us? But subsequent developments in physics – conservation of momentum, Newton's laws of motion – changed the context in which such a question might be asked. Now we know that objects that are moving freely continue to move along a uniform trajectory, without anything moving them. Why? Because that's what objects do. It's often convenient, in the context of everyday life, for us to refer to this or that event as having some particular cause. But this is just shorthand for what's really going on, namely: things are obeying the laws of physics.

Likewise for the universe. There is no reason, within anything we currently understand about the ultimate structure of reality, to think of the existence and persistence and regularity of the universe as things that require external explanation. Indeed, for most scientists, adding on another layer of metaphysical structure in order to purportedly explain these nomological facts is an unnecessary complication.

However fundamental you think the "causal principle" may be, modern physics is not done that way.

You're making statements about events or phenomena that happen within the universe, and then taking a gigantic, unfounded leap to apply the same principles to the universe itself. How could we possibly have a prior reason to expect the absence of all existence? Not the existence of some specific thing, but existence, in the broadest sense.