First: I wholly agree that my idea of God has no volition and is not equipped to care about anything we do. This is the view of God I'm defending, not a personal God.

Why is the idea important, then?

Good question -- I've been anticipating it for some time now. There are three reasons why the idea is important.

(1) Many people (especially scientists) believe in this God. Many/most world religions actually assert a God that is much more more like the God I describe than you might think. So I would like atheists to understand that when they assert that belief in God is irrational or absurd, they are really (usually) just making arguments that there is no personal God, which is annoying to theists that believe in the impersonal God. Perhaps mostly because as a result of the identification God=Personal God, they can't express their beliefs in a meaningful way. For example, even after having sketched my view of God, it was still implied that I "suppose that the entire universe is the creation of some infinite mind-like thing with an unconditional respect for reason!"

(2) Many logical arguments against God don't focus on properties of God specific to a personal God (the problem of evil is a noteworthy exception). Since they argue that God of any kind can't exist, but then my watered-down do-nothing version of God can exist, what went wrong with the reasoning? My favorite example of this is the argument that a supreme power would be too complex to exist. (Are the fundamental physics laws too complex to exist??) So I would really like to learn, after all, how anyone can tell the difference between an logical argument and just a line of reasoning that conforms with your point of view.

(3) As humanists, we need to identify what we have in common and not exaggerate differences. I think a lot of people, theists and atheists alike, have an innate belief that the world must make sense. As some people have pointed out in comments to me, it is possible for them to hold this as a theory rather than a belief. However, I then suspect that our personalities or the way our mind is structured is really quite different. And this difference is not a good reason to think of most of humanity as idiotic. I strongly assert that what theists really can't let go of (even the ones who believe in a personal God) is the idea of a meaningful/consistent universe. So practically, you'd have a lot more progress pulling them "sideways" towards a belief in an impersonal God than in no God. I've made a similar argument here.

Finally, there is an aspect to your question that I cannot fully address. It is: what difference does believing in God make if there's no reason to worship him and it would have no effect on my behavior? I have no response to this because I don't think it does make a difference. I have no objection to people being atheists. But I think some people innately do have a belief in God, and for whatever reason, it is connected with their motivation to explore the universe. If I don't believe in God -- if I consider it unimportant whether or not the world actually makes sense -- then I lose my interest in it. I might just take psychedelic drugs all the time. From observation of the true atheists here (who seem more or less reasonable) I suspect this is a difference in innate constitution.

I'm interested in learning how true atheists avoid this feeling of nihilism. I was actually once quite comfortable once with nihilism, but ultimately rejected it in favor of belief in an objective external universe. Which is why I am so interested in how other empiricists organize their worldview. When I say that my belief in God is innate, I should qualify that it may only be innate when I am simultaneously being an empiricist.