>So for all intents and purposes, the cage generates the same DC electric field that it would generate if it were simply affected by the charge placed inside.
I think what he means when he asked what you are on about is what is the difference between "protects" and "shields"?
You said:
> Faraday cage complete protects the interior from external charges but does nothing to shield the interior from the external charges
So you are saying that the interior IS protected from but IS NOT shielded from the exterior charges. Most people would expect "protected from" and "shielded from" to mean the same thing. Hence the confusion.
>So for all intents and purposes, the cage generates the same DC electric field that it would generate if it were simply affected by the charge placed inside.
https://en.m.wikipedia.org/wiki/Faraday_cage