Copying my thoughts from there which haven't changed:
>To which I say, are you really going to avoid using a good tool just because it makes you puke? Because looking at it makes your stomach churn? Because it offends every fiber of your being?"
Yes. A thousand times yes. Because the biggest advantage of Markdown is that it's easy to read, and its second-biggest advantage is that it's easy to write. How easy it is to parse doesn't matter. How easy it is to extend is largely irrelevant.
Markdown may or may not be the best tool for writing a book, but Markdown is the best tool for what it does - quickly writing formatted text in a way that is easy to read even for those who are not well versed in its syntax.
I don't want to write a book. If I did I'd use LaTeX before RST. I want something to take notes, make quick documentation and thread comments.