[anotherevan]

You've pretty much said what I was going to say. I think John was absolutely inspired in coming up with Markdown, but was a terrible steward. Or perhaps I should say he was unwilling to steward it.

My impression was he pretty much threw up a Perl implementation that was good enough for what he wanted, refused to refine it at all, and declared by the power vested in him by nobody in particular that if any parser implementation differed in behaviour to his (like, to fix bugs or make it better), wasn't true Markdown and wasn't allowed to be called Markdown.

Or perhaps I am being uncharitable in my interpretation of events.