It's not. Academic linguistics attempts to avoid value judgments entirely and rely on observations of how typical users of a language actually communicate.
Value judgements on language use are typically the province of high-status individuals who use language professionally (e.g., writers) or who teach language to others.
Academic linguistics attempts to avoid value judgments entirely and rely on observations of how typical users of a language actually communicate.
Which may of course include studying the value judgments made by language users (sociolinguistics) .
Linguist Arnold Zwicky has named three linguistic 'illusions' which seem relevant to cognitive bias. They are:
Zwicky talks about them here, and in not so many words links them to the standard bias of selective perception.
As an example, here is an exerpt via Jerz's Literacy Weblog (originally via David Crystal), regarding text messages:
It is my conjecture that these illusions are notable in areas other than linguistics. For example, history is rife with allusions that the younger generation is corrupt, and such speakers are not merely referring to their use of language. Could this be the adolescent illusion in action?
So, are these notable biases to watch out for, or are they merely obvious instances of standard biases?