I’ve been reading Daniel Dor’s manuscript Language as a Communication Technology (available here), and found this observation on grammaticality judgements insightful:
When a speaker follows the conventionalized rules to the letter, the endproduct (the actual fragment of speech) is judged by the other members of the community as grammatical. When making this judgment, the other members of the community are not interested in the fragment of speech itself. They ask themselves whether the speaker has followed the conventionalized procedures established by their community. They do not ask: ‘Is this sentence grammatical?’ They ask: ‘Does the speaker sound like one of us?’. Grammaticality judgments are always identity judgments (as the sociolinguistic literature shows). Eliciting grammaticality judgments from native speakers is thus always a political act, and grammaticality judgments are always methodologically complex, variable and vague. Speakers are defensive about grammaticality judgments: As far as they are concerned, it is their very membership in their speech communities, not the sentence they are presented with, that is being tested.
Dor, Daniel. 2010. “Language as a Communication Technology: A Proposal for a New General Linguistic Theory.”