Fair enough, I agree it never occurs. I still don't think that lack of conceptualizing and reflection on questions of origin would be considered agnosticism though. I think there is the variable of 'beingness' experience that leads the cognitive mind to reflect upon itself. This is where the birth of symbols and models come into being, in the spiritual or religious sense. What my argument would be is that "something" is experienced that leads to questions and models. It doesn't begin with an idea, but a sense of being. I want to touch a little more clearly on this in a second...
But this is exactly the problem of this "myth of the given". The myth is that you think you can overcome the subjective through objectivity. You cannot. So-called "objective modeling", is firstly completely saturated with linguistic structures which shape and limit the conceptual mind itself. I assume you are familiar with the field of semiotics? But what is more than simply this is my point that the subjective self cannot be disregarded, or itself be objectified. Reality at its heart is an experienced reality of which you are that reality itself experiencing itself. It cannot ever stand outside itself and begin to hope to see reality as it is! At best, you end up with a two-dimensional stick-figure reality that does not include the individual looking and experiencing itself. That is not reality, that is a caricature of reality.
To not explore the subjective "as it is", is to look at best at only 1/2 of the world. It requires a thorough understanding of how the subject sees and interprets the world - not merely just getting better data, but a deep understanding of the interpretive mind itself, and secondly, it requires expanding ones very own consciousness through the exploration of the subjective self, interiorly. That action, that self-development through subjective exploration, in fact changes how what it perceives "objectively" is filtered into itself and thus altering its own reality, and by effect, the objective world itself through interaction. In short, to say the least, the myth of the given is aptly named: Myth. It is in its own right equal to any other origin myth in the world, defining the world through an idea from itself. But because it is the set of eyes looking at the world, it never sees itself. It assumes it can find it "out there". It's like trying to find your eyes outside yourself while you are looking right through them the whole damned time.
Bah...
All atheism is doing is changing the stick figures from a magical god to a mythological view of reality as solely a rationalistic matter. It's in essence just simply a more sophisticated myth. That's all. There is no "it" to get closer to. There is only an unfolding and expanding point of view. The only way to escape the illusion is to transcend any and all conceptions of it into subjective being itself. If you want to talk about the true "default position" it would be nonduality, Enlightenment, which transcends subject/object dualities. It is "being" that is the default, not ideas about what that is.
Math and logic exist as mental ideas. Show me the square root of a negative one laying around in nature. The point is, it is the subjective itself that that mathematical reality resides in. It seems rather self-contradictory to then say we can ignore it.