As opposed to denying the existence. We know?, sense?, acknowledge? there is/is not a higher power. We don't know and are therefore free to demand proof. We simply do not have enough information to freely embrace the idea. That said, most of the agnostics I know try to cover all the necessary bases and leave our options open. Nothing could be worse than to find out I was wrong all these years about heaven so I do not reject, while trying to live a good life.
I wrote a lot and said nothing! That's the key!