Not sure I totally agree with that post though. In my opinion, if you understand the English language and can convey and communicate stories legibly somehow through a bunch of words stuck together, then, yes, you're a good writer (or have potential to be a good writer). Nobody is a bad writer. You may not be good at maybe expressing certain things, but there's always room for improvement. And was that message really sent to that person as, "You're Not a Good Writer?" Like...with ALL capitals? Wow, yeah. Okay then.