In the traditional writer's workshop, you write something, it's passed around, and people make comments. Depending on the workshop, a good portion of the feedback can be useless. And it's quite possible that few or even none of the others are trying to write the same sort of thing as you, so you don't have a good source of contrastive examples.
Read the SO response he got again. Near instant feedback, from a peer group, with counter examples to show what worked with the readers and what didn't. Faster, better quality feedback that leads to accelerated improvement.
Also, the site admins have cultivated a peer pressure of having answers/questions in good English on the site forcing people to sit down and formulate their typing instead of bashing the keyboard like it happens on other programmer forums. This is similar in effect to the editorial guidelines on HN, the same link on Reddit gets a very flamebaity headline whereas it's pretty tame on HN because of peer pressure.
Write more. Thanks. Already knew that.
I hate to sound snarky, but it's very ironic -- this entire post had the feeling of somebody sitting down to make themselves write something, anything -- without developing much original thought. In fact he quotes his cofounder quite a bit instead of coming up with insights of his own. He mixed together two very subjective ideas, "what makes good programmers" and "what makes good writers" in a way that didn't manage to shed light on either one. At least to me.
Communication is important, yes. Am I missing something? Was there something else?
Like I said, not trying to attack the writer, and I apologize if my tone is harsh. I know many times I have to write things over and over again, coming at the same topic from multiple angles, before I really nail it. Perhaps this is what's going on. (In which case I begin to wonder why it got so many votes)