For me it is all about the desktop space, there is no way I could productively use 4k @ 27" or even 32" without squinting or sitting absurdly close. Don't get me wrong, I'm sure it looks outstanding... and is more than usable with DPI scaling, but again looks just wasn't my goal with this purchase, even though this VA panel does look great IMO.
My productivity has really been helped out just having so many things visible and accessible at the same time. Just to give you an idea of what is possible with this set up (sorry for the bad pic, but you get the idea):