This blogger does not know the market better than the large and profitable manufacturers selling into it. The manufacturers have real numbers backing their decisions – not subjective aesthetic and ergonomic hand-waving. If customers weren't choosing (and even paying extra for) for the numpad, it'd disappear quickly.
HP shipped plenty of laptops with massive heat issues (literally painful to the touch, even sitting idle at the MS Store).
To think that OEMs always know best is wishful thinking. Although in the case of a numpad on a large style laptop, I'd probably prefer it.
The only good thing is that Apple is showing them up, so they're finally responding in kind, rather than racing to the bottom against Dell and HP.
As far as vertical space, which you argue as a positive of the 6-row layout, is negated by the fact they switched to a less vertical screen, and hence, keyboard.
Edit: As far as Lenovo doesn't know what they're doing... do a screw count on modern designs. Look at how much work is involved replacing the most common part (fan) - you've got to take _everything_ out. I've no reason to believe the high-level technical decisions are being made more intelligently than the obvious lack in quality at the low-level.
Even those crappy short screens: since businesses are buying them in preference to alternatives, they must find something about the cost and form acceptable. For business-focused machines, used by non-technical employees in brief spurts with a single full-screen app to get specific things done, a small screen may be preferable! HN commenters and coder/designer bloggers are not the customer.
What alternatives? There are no business laptops with full screens on the market. Lenovo offered 4:3 and 16:10 models that were otherwise comparable for a very short period of time. Buyers, from what I remember of the period, did not tend to prefer the 16:10 models. I'm not sure if anybody else had a comparable overlap. The switch from 16:10 to 16:9 was even more abrupt.
You are assuming that consumers are making rational and informed choices. The fact that people buy numpad-equipped laptops does not mean that they prefer it, but rather it means that it is what is being sold to them.
If there is a minority that is willing to pay extra for the numpad, and a majority who are ignorant about the compromises involved and thus ambivalent about the choice, then of course manufacturers are going to cater that minority and squish couple extra bucks while sacrificing the majority. But that doesn't mean that numpad would be beneficial to the ignorant majority.