Sometimes, it is simpler to claim atheism then it is to explain why you cannot stand any of options available on philosophical grounds.
Speaking only for myself.
I often claim atheism, even though I am not a hard atheist, because it simplifies a discussion. I find it most plausible that religions, even the ones with little of a God image, are all fictional.
Completely abstract concepts that don't exist in any objective way.
But most theists cannot grasp the simple notion that, like all other religions, their religion looks like fiction to me. And it also looks like fiction to the rest of us, from non-theists to believers in other religions. Christianity looks like fiction to a Muslim. Hinduism looks like fiction to a Christian. The Greek pantheon looks like fiction to a...
You get this? Religion is obviously fiction to practically everybody, except theists who believe that they are so special that they understand the unknowable better than anyone else.
I'm a non-theist because I agree with the Muslims about Greek pantheon, and the Christians about Hinduism, and the Native Americans about Judaism, etc. etc. I agree with all religious people about religions they don't happen to be biased in favor of.
Tom