how you gonna “control” an audience if you can’t even control yourself or your instrument?
Fluency doesn’t mean that we play complicated stuff or know all the classics, it just means that you can say what you want to say exactly when you want to say it. This could mean/necessitate different levels of proficiency for different people.
The aim of that is to achieve a level of connection with the tool of expression (in this case a guitar) that allows us to follow through on what BB King said: no matter what you play, just make sure it’s the truth.
In Capoeira we say that we don’t train to do Capoeira, we train to remove the limitations that keep Capoeira from playing us. I view it similarly with instruments.
I agree that standard tuning is not necessary to achieve that connection, all that was argued earlier is that switching between tunings constantly might keep somebody from getting to know the instrument and hence hinder their ability to express themselves intentionally and/or intuitively on the instrument.
Finally, I’d also argue that music has little to nothing to do with control over anyone. It’s a form of expression that has the power to move. Express yourself and make sure it moves you, maybe someone else will be moved by it too then.
@Clancy not all here a response to you, hope that’s clear