Wake sleeping screen with mouse move not click?
I believe the wake on click issue has more to do with the pointing devices shipping with the preponderance of new Mac systems: wireless keyboards, mice or trackpads for desktops and laptops.

There are two potential reasons for a click:


To maximize battery power, wireless keyboards, mice and trackpads power down when not in use--just like computers. 
Today's mice are all optical (laser or otherwise) and they turn off the light sources when asleep. The device does not register a movement until awakened. Wired mice might still wake a computer on movement.


I also don't believe the computer sees a difference when "waking" from any of the low power states available to it, be it a dimmed screen, a screen in lowest power state, or the computer "sleeping". A device "click" initiates full power mode.