simply pressing ALT+F4 didn't do it? (of course you had to click the desktop first)

That still worked yes! But I don't think most people knew about this. You just gave me flashbacks to those days working at the local college, we would do this to restart all the machines in a classroom, we had them all on Deepfreeze so it would purge anything students downloaded / installed. We had other remote ways of doing it, but it was fun doing the shortcut too from time to time.

It did. To some extent it seems like it was a telemetry mistake that some of the easier mouse controls (an actual button for start rather than gesture; a missing obvious power button; not having a simple mouse button to get to the Charms; etc). Windows users opted into Windows telemetry all must have seemed to be keyboard-heavy (probably because only certain types of power users, such as myself, were opting in to telemetry). All of the keyboard shortcuts still worked. Some new keyboard shortcuts were added. Windows 8 was extremely useful from a keyboard shortcut viewpoint. (The Charms made a lot more sense from the keyboard.)