As a systems I guy I completely agree with this. One of the things that was interesting about X11 is that it draws an API "wall" around the stuff involved in pr

As a systems I guy I completely agree with this. One of the things that was interesting about X11 is that it draws an API "wall" around the stuff involved in presentation. Many folks don't remember this but we had X "terminals" which was a computer system that did nothing else except render the screen and handle the input. In that compartmentalization there was nothing else competing for attention. You didn't get USB bus contention because there was just the one mouse, ever, on the line between the user and the X11 server in the X terminal.