I hope some more thought goes into the usability as well. I find the syntax for links confuses a lot of users for whom I have enabled mark down editing. Wiki style [[link text]] works great if you assume links have no space or maybe something similar. Similarly the syntax for images has also always bothered me.
I have no problems remembering the Markdown link format, but I never remember the expected order in what you describe as "Wiki style" (which is really a style employed by some wiki software - there are plenty of wiki software that uses other syntaxes, including Markdown)
