It's because said independence is a goal of play, not specifically because it came from the GM. You're trying to inject an "Us vs. Them" element into this that doesn't have to be there.
Irrelevant by what metric? Just because you can get same mechanical effect via another means does not mean the fiction is irrelevant.
Honestly I'm having a hard time even processing this response.
I don't factor that into the roll. I might factor it into whether or not there is a roll, or how often. But what might be there has nothing to do with how sneaky the PCs are.
You are trying to support your point by referencing the words of a prominent figure in the hobby whose stated views in this circumstance align with your rhetoric. How is that not appeal to authority?