I've seen someone close to me do it, and I still don't understand. I've asked her to explain why she fumbled around trying to perform a simple cursor move instead of moving the mouse, and I got a vague "it's easier" (it wasn't easier).
Same here. I couldn't understand it until like you and the comments before, saw younger generation all thought screens by default should be touchable, and other people casually scroll on the display and then return to keyboard for typing.