Markdown is designed to be easy to write, and, even more importantly, easy to read:
A Markdown-formatted document should be publishable as-is, as plain text, without looking like it’s been marked up with tags or formatting instructions. – John Gruber
This principle has guided pandoc’s decisions in finding syntax for tables, footnotes, and other extensions.
There is, however, one respect in which pandoc’s aims are different from the original aims of Markdown. Whereas Markdown was originally designed with HTML generation in mind, pandoc is designed for multiple output formats. Thus, while pandoc allows the embedding of raw HTML, it discourages it, and provides other, non-HTMLish ways of representing important document elements like definition lists, tables, mathematics, and footnotes.