Explanations should be knowledge-bearing. The God-one is phony, a pseudo-explanation, because it doesn't explain how He affects the changes that people maintain that He brings about. How does He do miracles? How did He cause the Big Bang? How does he design things? By magic?
Without specifying how He does all that, then God did it means nothing and He bears no knowledge.
Theories should be falsifiable. When we skeptics investigate, we find natural causes and explanations sufficient in explaining matters. Our Ockham's Razor cuts Him off as an explanation as He adds nothing to our explanations, being parasitical on them and requiring convoluted, ad hoc explanations Himself. He explains no more than demons do for my psychological problems than psychology itself does or what mechanics does for mechanical failures than do gremlins or Thor for the weather and climate. Here then is the principle of simplicity at work.
However, theologian Richard Swinburne claims that He is simpler than those causes as He is a simple entity. No, the Razor doesn't refer to the number of entities but rather to the simplicity of the theory itself. And so Swinburne's attempt fails.
Anon on the other elements of successful theories.