because [][] is used for [reference-style links][daringfireball.com], which allows you to write stuff like I did and still have []() handle both URIs, absolute paths or relative paths.
All of those debates about the link syntax is a complete and ridiculous bikeshed. Any solution I read around here above about making it "smarter", "better", or whatever just end up in making it awfully and needlessly more complex and ambiguous, and yet another bikeshedded standard. The way it is currently is totally KISS: [x](y) => link (i.e a href) and [x][k] + [k]: z => resolve k then link to z. Escaping ')' is trivially solved by the second case.
All of those debates about the link syntax is a complete and ridiculous bikeshed. Any solution I read around here above about making it "smarter", "better", or whatever just end up in making it awfully and needlessly more complex and ambiguous, and yet another bikeshedded standard. The way it is currently is totally KISS: [x](y) => link (i.e a href) and [x][k] + [k]: z => resolve k then link to z. Escaping ')' is trivially solved by the second case.
[daringfireball.com]: http://daringfireball.net/projects/markdown/syntax#link