Response to The English teacher's Red Pen

I have never been the student with perfect grammar or spelling. I remember several instances in which I turned in a clean white paper that I felt proud of, only to receive a dark red, marked up version of what was previously my paper. I don't think anyone can really say that they haven't felt that pang of disappointment when a teacher overlooks some incredibly genuine ideas because they are too focused on misspellings and bad punctuation. This article is defending students like me and promoting the idea that, hey, maybe some English teachers should lay off a little.
On the other side of this argument, knowing core elements of writing is almost as important as the unique ideas that are being written down. For instance, knowing and understand the engine of a car can help the driver know exactly how the car should be driven. It also helps the driver recognize problems with the vehicle, before it's too late. Just like the engine of a car, it is important for students to understand the mechanics that go into a well-written paper. Knowing this can help a writer recognize a problem and change it to make their paper better.
Now Im not saying that English teachers need to focus on grammatical errors and mark up each student's paper until they get it right. Like I have said before, I have been that disappointed student. But having a good grammatical foundation is important. However, it is not the most important.