Machines have makers. They don't just pop into existence without a maker. The machine-Maker of the universe is God. Why would this Maker have to be God? Because the power and ability that this universe-maker would have to have to make this complexity, fits our definition of the word "God."
Issues with your argument:
1. Your classification of the universe as a machine would allow anything to be classified as a machine, so it is not meaningful.
2. You have not shown that a machine must have a maker and cannot exist without one. You assume it based on your biased observations. Lack of observations of a black swan do not prove that one doesn't exist.
3. You say that a god must be the creator of the universe because it is able to create it. That does not preclude something else from creating the universe. Perhaps your god found or inherited or even stole the universe after something else created it?