Tradition is hardly the primary or even sole factor we use to determine the definition of a term unless you're using a prescriptivist framework for linguistics
Not about linguistics or semantics it is about equivocation, let's avoid it. Secondly and most importantly if anyone applied your method of claiming their position on any knowledge issue is "the default," and therefore doesn't apply to the known rules of justification in epistemology we would laugh at them. This is absurd. It would destroy all knowledge completely, not just religious knowledge.
It seems that you are making a special pleading that religious knowledge claims are different than all other knowledge claims.
I wouldn't say atheism is the default position, but nontheism in that the latter is more a general lack of belief, while atheism is at least cogent of arguments for and against the existence of God by contrast. A child doesn't innately have God belief anymore than they innately have morals in the complex sense we'd grant around 8 or so (at baseline anyway)
child doesn't have rational beleifs about evolution or inflationary cosmology either.
Rocks are atheists. Lol.
Why keep dodging epistemic requirements for knowledge claims with these Rediculous false analogies. There are good atheistic arguments but New Atheists slogans are absurd. Read Graham Oppy or JH Sobel. And move away from the poor quality of Richard Dawkins and his ilk.
The question becomes justification rather than certainty: I may, in this simplistic notion of having to make that knowledge claim absolutely, state I don't think there is a God, but that isn't the same as claiming I'm saying it's justified to the extent someone would claim their belief God exists is, which is not subject to critical thought in contrast to me simply finding the arguments for God's existence wanting.
Not sure how "certainty" came into the discussion, all parties agree (since Descartes ), that we don't have epistemic certainty on claims other than "I exist."
So I do agree that various knowledge claims can be justified with the same arguments and at one time a person things that belief is barely warranted and later not warranted or completely warranted without changing the justification.
Now we are getting somewhere. It may be perfectly warranted to beleive as most cosmologists do, in the inflationary model developed by Alan Guth is the best explanation of our current universe even though we cannot gain any direct evidence of the theory due to event horizon limitations. Alan can innumerate half-a-dozen or so reasons then use them cummulatively to argue that his model best explains the data we have currently.
As a Buddhist, I would expect you to defend your claim that Buddha more accurately answers our religious questions: how did sentient life arise, how does one get meaning in life, how should one live morally, how do we relate to God if they exist, is God personal or impersonal, where will I go when I die.
These are religious worldview questions.
Buddhist have different answers than JudeoChristians than Hindus, than atheists,etc.
The fact that atheists can and do answer these questions demonstrates that atheism is a worldview.
Agnostic atheism as distinct from gnostic atheism, is helpful in making the nuance of the epistemological certainty and justification to a degree, because one is making teh strong claim based on certain justifications while the other is saying that extraordinary claims require extraordinary evidence and are not making a certain claim
Extrordinary claims such as the claims of Einstein that Newton was wrong about his conception of the universe, or max planck's quantum theory, or Alan guth's inflationary cosmology, those types of extrordinary claims that waited decades or half-centuries for evidential confirmation, and longer to be added as "knowledge" in science?
Again I expect no special pleading. There is no argument that can be given raising the epistemic bar for religious belief that doesn't have the unintended consequence of destroying knowledge across all other areas of knowledge.
Further Scientism is self-refuting so one does not have the ability to backdoor special pleading that way either (not that you have argued that way).
Agnostic is just a descriptor of some level of non knowledge.
We all have 1000s of beleifs that range from fairly certain to fairly uncertain.
We don't want to lose sight of the knowledge project here. When we attempt to gain knowledge in any subject we read textbooks that argue for, and engage arguments against a knowledge claim. Early we may believe are professors, later in grad school we become inundated with the other views and other evidence and argue for or against views we held earlier, based on our own research.
"I don't know" doesn't have to be a knowledge claim to be intellectually honest in regards to the claims made regarding the existence of a transcendent being. Sometimes it's as much a matter of responding to a claim rather than making an assertion of your own
"I don't know" is definitionally, necessarily (philosophically speaking), NOT knowledge."
But your point stands! It is a great point! Here is a point worth building on.
When a theist builds an argument for God, engaging that argument with a view towards questioning facts, premises, soundness of arguments (fallacious appeals), or how good the argument is, is the proper way to engage!
One need not defend atheism to engage the theist.
I engage theists and call out bad arguments and fallacious appeals by other theist in my posts from a couple years ago entitled, "Tricks Theists Play." A call out the tricks of guys like Ray Comfort and Ken Ham (who practice the same bumper-sticker rhetorical flourishes and manipulative propagandistic approaches as the New Atheists practice).
That type of epistemic inquiry is proper. Arguments stand or fall on their own.
Similarly, the knowledge claim "There is no God."
And the claim, "I'm agnostic," need not be evaluated at all. It is a claim about one's belief. Not a knowledge claim.
To sum up:
All knowledge claims are evaluates (not assumed) using epistemic justification methods sans special pleading.
A worldview answers where we came from, how we should live our lives, how we get meaning, how do we relate to God or what was god's role in this world if God exists, what happens when I die?
Unless someone says "I don't know" to all of those questions, then they have a worldview. We don't expect all people to have fully developed worldviews. Less education means less ability to justify views but doesn't precude holding true views. Less development (12-year olds will have less capability to engage these questions than adults, babies will have no ability) mean less justification, but doesn't say anything about what is real in the world!