"Atheistic Agnosticism" is an oxymoron. The term has grown popular over the last ten years, but it's a cowardly way to not actually take either position. The goal seems to be to avoid being held to account for specific positions by having a foot in both worldviews.
Classic atheism proved to be an unsupportable claim, so they backpeddle toward the agnostic position, but still desiring the comfort of atheism.
"not actually take either position"
That's the point. Given the evidence it's unreasonable to take either position. Why is it cowardly to admit you don't know? That is bravery not cowardice.
I have no problem with someone who "doesn't know" but that's not the claim with an "Atheistic Agnostic". One term says, " I don't know" the other says "I do know". This is a logical fallacy. One cannot both know and not know. Right? Much like a square circle it's a logical paradox. Have the courage to take a solid position on the issue then we can chat about it.
What you provided aligns perfectly with what I've said. You don't get to define atheism so that it makes it easier for you to argue against. That's just petty.
If the people that identify with and label themselves atheists have made an effort to have a more nuanced definition published that does nothing to strengthen an argument against it.
Do you know how the English language works? If people start using a word the way that it is used is what the word becomes in a dictionary. Dictionaries respond to popular usage of words not the other way around. Language evolves get over it. You are just distracting with semantics at this point.
Let's forget about the word and focus on the concepts. An agnostic lack of a belief in gods is seemingly the only reasonable stance to take.
Agnostic = I don't know.
Atheist = I lack a positive belief.
These are completely logical to pair.
Only if you alter the definitions the way you have here.
Atheist have recently been trying to change to this new definition precisely because it is a positive belief that there is no God. The definition you have offered is actually closer to the definition of agnostic. Maybe that's why you see the compatibility between the two.
I don't think "Atheistic Agnosticism" is coward. The person must be courageous enough to say that he doesn't know the truth and sincere enough to say that he doesn't believe simply because it's his opinion.