…so many folks who identify as theist think that people who identify as atheist assert that there are no gods? Is it a willful mis-definition? Do they really not understand the difference between (a)theism and (a)Gnosticism? Or do you think they push it because it so handily fits into their narrative?
Theist = belief in god(s)
A(theist) = without (belief)
I feel your pain.
I believe they misconstrue the nature of atheism because there is declining church attendence, and they want to misrepresent what atheism is in order to suit their agenda and park more asses on church pews.
It also suits their narrative to portray atheism as an “enemy” of Christianity, so that they can take advantage of a supposed conflict between right and wrong . . . with atheists being the Satanic stooges.
Because atheist is a cognitive assertion. Atheism isn’t an epistemological assertion.
Many theists assert that atheists actually do believe in gods, but just won’t admit it to themselves.
That’s where they (theists) are misguided. A cognitive assertion isn’t an ontological assertion.
Please describe what this phrase means to you.
Sure.
Ontological Assertion
What it is:
A claim about what exists, what is real, or what the structure of reality is, independent of human minds.
Cognitive Assertion
What it is:
A claim about belief or conceptual content—what a person believes, thinks, or means.
Epistemological Assertion
What it is:
A claim about knowledge, justification, methods of knowing, or the limits of knowledge.
So, saying, “I hold no beliefs in any of the gods described to me.” Is, according to you, a cognitive assertion?
That would be a particular cognitive assertion, not a general cognitive assertion.
It’s a complete cognitive assertion relative to the “gods described to you”. However, it is not complete relative to all possible gods that can be described.
I never asserted it was.
FFS slow down! You have written over 100 posts in a week and a half.
All the boys want the belle of the debutante ball! 
It’s not a complete cognitive assertion…
It need not be an assertion at all, you already admitted newborn babies don’t make cognitive assertions, they would by necessity lack belief in any deity or deities, as would someone who had never encountered any concept of deities. So no atheism is not a cognitive assertion, though some atheists do make such an assertion, though of course claiming to lack a belief would not have a burden of proof in and of itself. Atheism is not a claim about the existence of deities / gods.
Some apologists revel in poking this particular bear, but they usually end up citing fairly obscure philosophical tomes, often with a religious bias.
Atheism
noun
disbelief in the existence of God or gods.
The OED even used a capital G for you look.