I think this is in part due to how quickly software is developed. Since reqs > mvp can be hours, days, or at most weeks, there is a lot pressure on designers for quick turn around.

My friend is an Industrial Designer, and works on Faucets, probably one of the last interfaces replaceable by a touch screen. Their design pipeline is years long. They build multiple prototypes and mock them with real humans, and get the space to actually watch people use them. I have very rarely seen a UX designer get more space to experiment than a InVision mockup. So of course what they design is disconnected.