Teaching writing: FSP's "Can't, Don't, or Won't?"

Female Science Professor has a post up called "Can't, Don't, or Won't?" in which she relates something that she heard from a "Writing Expert":

She said that she understands that many professors get frustrated when their students keep making the same mistakes in their writing, but that most people can't learn from their own writing mistakes, even after having the mistakes corrected and explained. It is essentially a learning disability. . . .

Are they lazy or careless? Do they just expect others to fix their writing problems? It is not difficult to find laments such as this in professor-blogs.

But the Writing Expert said that most people can't fix these problems. She said that some can, but most can't. She said "can't", not "won't" or "don't", indicating a lack of ability, not a lack of willingness or attention.

Have any of you heard this? I know that patterns of errors can be difficult for students to detect (thank you, Mina Shaughnessy, for your work all those years ago about this!), but "can't" seems like a tricky term to use unless the student is diagnosed as learning disabled.

It's hard to spot errors in your own work, and it's even harder for students to do so, although they can often see the problems in someone else's paper, as one of the commenters at FSP's place says.

I know that despite the claims of minimal marking enthusiasts, sometimes students just don't get the point of those mysterious little check marks in the margins. They get just as frustrated and hopeless with that kind of "I know the answer and I'm not going to tell you" marking as they do with papers that are "overmarked" with every little item pounced on and killed in a pool of red ink.

Grading is a balancing act between encouraging the students to take responsibility for their writing by letting them figure out the problem, as in minimal marking, and helping them out by explaining what's amiss so that they can do better next time, as in traditional marking with marginal comments. We ought to know that they don't make those mistakes to spite us, but because they don't (can't?) see them.

But doesn't "can't" sounds a little defeatist, as though the students can't learn and we can't help them to learn? If a student "can't" learn to correct an error, does that mean it's incumbent on us to ignore it? Or does it mean that the student shouldn't be in that particular class in the first place?

I have more faith in students than that. I'm crossing "can't" off my list of reasons not to learn to write better.