So the way I understand it theological noncognitivists say that the definition of the concept of "god" is incoherent and thus cannot be discussed, since being nonsensical.
Wikipedia gives the following example:
The sentence X is a four-sided triangle that exists outside of space and time, cannot be seen or measured and it actively hates blue spheres is an example of an unthinkable proposition. Although the sentence expresses an idea, that idea is incoherent and so cannot be entertained in thought. It is unthinkable and unverifiable.
To make it more familiar let me play the devil's advocate and assert god is a supernatural being that exists outside of our observable universe, cannot be seen or measured unless god wants us to see it. I understand that it is unverifiable but why can't this assertion be entertained in thought? Why is it unthinkable? I can certainly picture a being that is above the physical laws we observe, I can even picture it being so much more above that we will never be able to see it unless it wants us to.
Let's say in the center of a black hole lies a wormhole which connects to another universe. That's also unverifiable but it's an established theory in physics (Einstein-Rosen bridge).
There is no observational evidence for wormholes, but on a theoretical level there are valid solutions to the equations of the theory of general relativity which contain wormholes.
In short there's no evidence for wormholes and there's no evidence for parallel universes. There's no evidence for supernaturality either. Yet the first is considered to be something we can work on and the second is not being accepted as an idea that could be discussed (by ignosticists).
That's probably an easy one for you, I just fail to connect the dots (again *cough*).
Hit me