IMO it applies to the designer (i.e., myself) and the electrician (i.e., yourself). One thing that you and I have in common is that some aspect of our licensing requirements includes the requirement that we comply with the code. A homeowner has no such requirement imposed upon them. The NEC is not merely unenforceable to the HO, it cannot be applied to a HO, no matter what words it contains. Nothing outside the book itself requires a HO to own a copy, or to comply with anything inside the book.
A code is not a "code," until some governmental body enacts it into law. There is a law in my state to the effect that the 2008 NEC applies to electrical installation work. The passage of that law is what caused the "NEC" to become "code" in this state. There is another law in my state to the effect that I, as a PE registered in this state, must comply with the NEC, in any electrical design work that I perform here. There is no law in my state that says that I, as a homeowner, must comply with the NEC.
That is the basis for my opinion on this subject. Essentially, the NEC is not an authority unto itself. The NEC does not and cannot say, "obey me." The NEC says, "here is a rule," and a governmental body says, "obey that rule." I know of no governmental body that has said "obey the NEC" to a homeowner.