>The use of the terms "correct" and "incorrect" suggests that there exists a universal ground truth, and my whole point in this discussion is that no such ground truth exists.
The universal ground truth is the intersubjective understanding of language norms.
>The only way to get around this is to establish a specific cultural context where a ground truth can be agreed upon (e.g., a style guide used by a particular publication venue).
Yes, and such context exists. The main prestige dialect in the US is General American, all other dialects are marked geographically, culturally, professionally or in some other similar manner.
The universal ground truth is the intersubjective understanding of language norms.
>The only way to get around this is to establish a specific cultural context where a ground truth can be agreed upon (e.g., a style guide used by a particular publication venue).
Yes, and such context exists. The main prestige dialect in the US is General American, all other dialects are marked geographically, culturally, professionally or in some other similar manner.