> For example, with a 27" 4K display many users will want to use 150% or 175% scaling to get enough real estate, but the image will look blurry

I use a Mac with a monitor with these specs (a Dell of some kind, I don't know the model number off the top of my head), at 150% scaling, and it's not blurry at all.

I also feel it's just fine. Not as amazing as the Apple displays, but I'll have to sit really close to make out the difference for text.