Some Article 100 Definitions work is hinted at in your choice of words.I was under the impression that any fixed and hardwired appliance or fixture requires a means of disconnect within sight or if not within sight is required to be lockable.
Plumbers install "fixtures", electricians install "Luminaires."
Compare the Article 100 Definition of Appliance to Luminaire, and it becomes a real hard sell to equate the two. We can spend a lot of words bandying this about, as has been done in other threads, but they are essentially not the same thing.
Also, pay particular attention to the last sentence in the Definition of Luminaire with respect to what Roger asked you in Post #18. An understanding of "Lampholder" is going to yield some interesting insights. And the specific configuration of a "Pull Chain Lampholder", with respect to your opening question, gets more purely to the point.