A RhetNet SnapShot Reply:
THE MAIN PROBLEM
Fred -- mostly I find myself in agreement with you, and always respect you. But I think we need to think about correctness and what it means rhetorically as well as thinking about what it means pedagogically.
You were worried ". . . about priming people for some correctness machine down the line (business? graduate school . . ." But the fact is that if I don't worry about my students' use of various grammars, they aren't going to have to worry about correctness in graduate school and business because they aren't going to get a decent job or entrance into a graduate program. Their writing skills just aren't (for the most part) up to the task.
And correctness is, in our culture, a major part of the perception of ethos -- writers who have, say, a consistent problem with agreement, are perceived as sloppy and even stupid.
It's all very fine for us to say that writing is communication and as long as we communicate, then writing has done its task, but I can't let my students send out a resume with spelling errors. The rest of the world will slam them!