I am suprised some of you don't see the difference between a recptacle that a six year old can plug a lamp into and a blank cover that a qualified person has to pull out the tools and ladder to get it working. I think George makes an even better point, how can you inspect that the switch on the wall that is required to operate the blank cover is properly hooked up?
And as far as what is the danger? I don't know, ask the same people who saw it fit to add this the NEC. My point is, that for whatever hazard is present to necesitate the requirement, that hazard is present until the light is hung.
