I think S/F has addressed this but I'll clarify if I can. (I'm not sure what I was talking about either. I'd say maybe I was drunk, but I have not been drinking.)
The adjective is not relevant on a functional level (i.e., the person's career choice, occupation, etc.) but it is (or can be) relevant when evaluating the writer's relationship to material (subject, style, etc.), the relationship of the "system" to a person, etc. Part of the "process" for each of us is to analyze our thoughts, words, speech, etc. in relation to the attributes of the person on whom we are focusing.
I often find it helpful to try to understand this in a way that is not loaded with potential bias. Instead of a minority, think of how we discuss a British writer. Do you have an issue listing the 10 great living (English language) playwrights without caring if they are American or British (or Canadian, Australian, etc.)? But if you are analyzing the legitimacy of an American writer penning British sensibilities, or some bias you might have against British artists taking US "jobs" in the theatre, would you hesitate? I presume not.