Heavy-duty parts can…
Heavy-duty parts can sometimes make more noise compared to "lesser" ones and give a less-refined feel.
I recently wrote about the 10-speed auto found in the Mustang and Camaro (it's jointly developed), and it turns out the whining sound is caused by the straight-cut gears, which actually contribute to performance.
I somehow doubt Nissan has done the same here, but that's something one can only confirm after taking the transmission apart.
As for the NISMO Z, they intended it to be a numbers car, which is a bit of a shame, hence the automatic-only option.