Whether it will prove useful like the above models still remains to be seen, but calling it "not science" seems ahistoric. Let's see if they can evolve the theory to the point where it can make novel predictions. If it never makes one, then the model is not useful. If it makes one but is proven wrong, then at least it will be wrong (rather than "not even wrong"). If it makes one and is proven right, then we will have made a big leap forward in our understanding of the universe.
I'm ok with either of these outcomes, but I don't get why anyone would want this thought experiment stopped before one of them is reached.