Can you really extrapolate something like Aristotle's Unmoved Mover into something you can call "God," given all the Abrahamic trappings that word (especially capitalized like that) has received? The Unmoved Mover redefines "god" to its minimum possible definition: a force that set the universe in motion. The Unmoved Mover is not necessarily eternal, is not necessarily omnipotent, is not necessarily omniscient...f**k, is not necessarily conscious or sentient and may be acting out of dumb instinct.
That was my thought, really. From the atheist scientistic viewpoint, the universe began with the Big Bang. The issue is, the proponents of that viewpoint cannot to their satisfaction account for how matter came to exist, much less in the configuration that allowed the Big Bang to occur.
Let's say then that it happened because a single proton decayed, just to throw something totally random out there. To identify that proton as God, which seems to me to be a natural application of the "unmoved mover as God" idea, strikes me as degrading to any notion of God or gods.