In his post Omics! Omics!: 10 Years of Omicing!, which reflects on the influences on his writing, Keith Robison says
The other person who deserves nearly infinite credit for making me think about my word choices is my father. Sometimes he strays into being a pedant and enforcing rules which have fallen by the wayside, but he did make me think when I spoke and wrote. I’ve seen some guidelines for helping students that counsel picking only a few major errors to mark, for fear of scarring the psyche of young writers. Dad didn’t subscribe to that viewpoint in the least, and I’m the better for it. In high school I treasured getting back a draft with red ink all over it; it’s a service I missed in college and beyond. That meant he had read it and thought about it, and my work was always better for it.
I think that this attitude is one that we need to see more of, both among students and among faculty. I put a lot of time into trying to provide thorough feedback on student writing, even though I know that it is not always appreciated. I also know a number of faculty who bemoan the low quality of student writing, but spend almost no time giving detailed feedback so that the students can improve.
There are times for triage—concentrating on the students whose work could benefit most from editing, while providing only minimal feedback to those who produce word salad or whose writing is very good—but I prefer to try to provide similar amounts of feedback for all students. For the word-salad students, my comments are mainly on sentence structure and paragraph structure, to try to have their writing make sense at least at a local level. The students in the middle get a mixture of different comments from punctuation to overall structure of the paper, while the top students get mainly get comments on trivial little details that can polish their already good writing.