I suspect the utility of a numpad is increased while the off center problems are decreased for touchtypers which is why there is such a divide.
Ah? I would have thought the opposite. I cannot touch-type at all (and you could promise me a million dollars reward, I still wouldn't manage), nevertheless there is one part of the keyboard I can use without looking, and it is the numpad. Possibly because it is a limited area with a limited number of keys, and the numbers are placed in a "logical" order (compared to letters on the main part of a keyboard).
I am bad at entering numbers on the top row, a I am forced to do on most laptops (and unfortunately, I personally find the pseudo-numpad, which requires using the Fn key or similar, utterly unusable; I never could get used to it).