The article says: "One of the first things people do [when they get a new piece of software] is go through all the menus".
Of course we do! That's how we learn what the program can do, not just how to do it. That's affordance.
Also, I think if the HUD is added to, rather than replaces, the menus, then the HUD has the potential to significantly increase discoverability.
I also hope this provides a nice, general way to introduce sciptability into applications, and that actions will be able to take arguments in the future. Or is that going too far?
The example for affordance I always use is the door handle example.
The pull handle on a door 'affords' pulling.
The metal pad 'affords' pushing.
(a keyboard button 'affords' pressing)
Essentially they look like they should be pulled, pushed and pressed.