A few years ago, I ran across a blog post where the author claimed that those who think that writing well is important sap the life out of creativity. She recounted how she was discouraged from sending a letter to Mad Magazine because her English teacher critiqued it too harshly.
I feel sorry for her that she let one person's comments keep her from doing something that to this day she regrets. How much do we read and hear that if we're really passionate about something we should go ahead and do it anyway? How passionate are you about something if one person can stop you cold? In the words of Scott the Nametag Guy: stand up, speak up, or get shut down.
The blog author cited an excerpt from Stephen King's book, On Writing: A Memoir of the Craft. In it, King describes a childhood experience in which he wrote a grisly story that horrified his teacher. Now, the teacher was horrified by the gory stuff that was in the story he wrote, not so much by the bad spelling. What she commented on was the gory details. The blog author tried to use this as an example of how teachers and others shouldn't harp on grammar and spelling and such.
That wasn't King's point. His teacher wanted to know why he was wasting his talents writing like this. Her words (quoted by King): "What I don't understand, Stevie, is why you'd write junk like this in the first place. You're talented. Why do you want to waste your abilities?" Not a thing in there about how he shouldn't even attempt writing since he couldn't spell. The teacher admitted that he had an incredible talent.
King goes on to say that he was ashamed of what he had written. Again, not by the bad spelling and grammar, but by the content. He says he spent the next forty years feeling ashamed about what he wrote.
Now that's a great example of how we should just keep on and do what we're meant to do despite what the naysayers say. However, this isn't a good example of how the "grammar Gestapo" should just leave us be.
The blog author made this plea to writers:
Correct English is the worst way to articulate something. If I tell you that at my last family reunion we ran woefully short of poultry due to an equipment malfunction, you don’t understand the situation as well as if I write, “my second cousin told everybody ‘We don’t got no fried chicken ’cuz daddy done broke mamma’s deep fry tryin’ to boil the tar off his lug nuts.'”