Well, that paragraph you quoted is indeed non-sequitur, clearly you can program computers to discover unexpected truths using their 'axioms', code their 'axioms

Well, that paragraph you quoted is indeed non-sequitur, clearly you can program computers to discover unexpected truths using their 'axioms', code their 'axioms' to be as flexible and fragile as ours and so on, but the assertion that the nature of the brain is a computing device in the sense we "information science people" refer to one, is far from obvious. Obviously the brain computes stuff, but we tend to be rather specific and we think of computers when we say computing device, which might or might not be able to simulate human intelligence, hence the strong vs weak AI debate. Trivially you can, with perfect information and sufficient technology, modelling neuron by neuron, create an electronic brain. The catch is, you would only prove humanOS runs on silicon as well as it does on carbon. Having a powerful enough computing device does not imply it can compute anything a different type of computing device can. We have the turing-completeness that indeed says this is valid for a subset of our current programming languages and hardware, but turing-completeness does not trivially apply to our brain. As an analogy, a ruler is a drawing device, but you can't draw a circle with it as with a compass. You can somewhat simulate drawing a circle by taking it very slowly using a certain clever algorithm, but it will never be perfect or else require infinite or virtually infinite time/space to do so.