Hahahhahahaha.. you probably wouldn't do it this way, because it would be a huge new machine, and that's way more expensive to develop and put into the line than playing with existing components to achieve a different surface finish.
Overall, I'd give them the benefit of the doubt as to why they are the way they are.. Germans are no slouch.. There's probably a design reason they're a little scratchier out of the box..
For example, when you inject the plastic, if the surface of the mold is super super smooth that might cause sticking or warping as the plastic is blown out during ejection or injection, so you might lose some tolerance there..
If you have a grittier surface, there might be a minuscule layer of air pockets between the plastic and the mold, so that way there's less sticking.. and it clears the mold more easily/ reliably. perhaps increasing the rate of production.