I certainly read Nietzsche differently to this author (and probably Kierkegaard too by the sound of it). I think a point both of them made was that truth can only exist within the context of an agreed upon set of axioms. If you accept that you can’t prove your axioms, then your not accepting that all beliefs about truth are equally valid, you’re only accepting that all beliefs about truth are equally capable of being proven (as in, equally not capable at all). From that perspective it’s easy to see why you might reject dogmatism.