"Ineffable will is simply that, ineffable. It cannot be described and cannot have attributes given to it. It is what it is." Trying to focus on driving a suitable distance away from the creature, Crowley considered that it was better if Aziraphale explained such a thing. The angel was always better at explaining ineffability. It probably had something to do with all those books he swam around in.
Thinking on Aziraphale again, Crowley started to forget himself, which when he did so meant that his s's came out with a hiss on them, not unlike a snake. "Sometimes it is best to just accept things as they are." And that was that. It was the best explanation she was going to get. "We are here because it wants us to be here."
It was a shoddy explanation, but it was the best he could and would be able to do. Crowley didn't spend a grand amount of time contemplating ineffability any longer where he would have had a grand philosophy on it all written and ready for educating the masses with. Even if he himself was a creation of the ineffable power.