Ah yes, the Hasselblad H6D-400C. I could use one.
The author of that article has a true point. Boiled down, it's that many [most?] photographers own more camera than they can effectively use in terms of output. Nevertheless he does miss some key points of the new 'Blad, and therefore is far from "proving" his thesis. "Why the hell do we need 400 megapixels? We don’t even need 100 megapixels, and I’ll prove it." ??? Not proven at all.
1)a The new 'Blad is not intended for everyone, or even a fractional percentage of everyone. Just because the author doesn't need it for shooting his iPhone wallpapers, doesn't mean nobody needs it for anything.
1)b Every technical innovation in digital imaging is first met with resounding cries of both "cool!" from people who don't understand or need it, and "what a waste!" from other people who also don't understand or need it.
But there are categories of photographers & artists who will be able to use it, once it exists, to do some super cool stuff that wouldn't have been feasible or even possible before. So let them at it.
1)c It's an application of trickle-down technology, just like Live View was a trickle-down of CMOS sensors. Hasselblad has had pixel shift digital backs for years now, and so the R&D of solving that issue is largely a sunk cost for them, I imagine. It dates back to a time when the single-frame resolution was a lot lower, and therefore the benefits of over-sampling in this fashion was relatively much higher. But since solving the problem was already done, they just needed to drop a new higher res chip into the mix, and poof... here's a new offering for the high-end market. Not a big deal, no reason to write articles demanding companies stop doing such things by proving/not-proving that we don't need them.
2) Pixel shift technology, which is employed by a number of vendors including Sony and Pentax on the more consumer-friendly end of the spectrum, is not just about getting more pixels. It's also about getting better dynamic range, better colour fidelity, reducing moire artifacts, and so on. In other words, it's about the very thing the author asked for at the end of his article -- "Let’s focus on making our cameras better, not bigger."
As a person who makes prints for a living, I recently made my first prints for a client who shoots the Phase One IQ3100. Those files looked absolutely stunning, and we delivered prints that made every bit of use of those 100 MP. I can't wait to dig into printing some Hasselblad 400 MP files.