You could say the same about most publications in theoretical physics. The point of this sort of thing is (1) to make predictions that can be evaluated on the basis of empirical evidence and/or (2) to help make sense of the empirical evidence; it is no fault that it doesn't itself contain or describe that evidence.

(I have no more than glanced at this particular paper, and make no claim that it's any good. But this is not a reasonable criticism.)