Agreed. The least they could do, if a numpad really is necessary, is put something of equal size on the left side. A macro pad would be novel, or even just a left numpad so that right-hand mouse users could enter numbers at the same time.
They could do what Apple did 20 years ago: Make them modular.
You used to be able to pop the trackball out from the right side of the keyboard area, slide the keys to the right, and then re-insert the trackball into the left side.
Do the same with a num pad, instead of a trackball. And for people who don't want the num pad, make available half-width blank inserts to occupy the space on both sides.
IIRC that original Macintosh Portable even had a numpad as an alternative to the trackball, to go on whichever side you wanted (and presumably you'd connect a mouse to use in stead of the trackball).
i wonder if splitting the alphabet portion of the keyboard down the middle and putting the numpad in between would work. It would look like some unholy abomination but may be more ergonmoic