Why not deism?

[Inqwizitor]

My understanding is that naturalism does not explain the origin of life, let alone the universe.

Science has not finished. So for the moment "we don't know but people are working on it" is better than installing some sort of holding belief.

Right. And there are theories about RNA I think, that it is some sort of bridge between inorganic and organic matter (I'm no expert). What I mean is, naturalism does not say why there is anything at all. It's denounced as a meaningless question. Deism doesn't require that kind of eliminative reductionism.