[Bockit]

Actually the markdown page on his site mentions exactly that as markdown's intention.

> The overriding design goal for Markdown’s formatting syntax is to make it as readable as possible. The idea is that 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. While Markdown’s syntax has been influenced by several existing text-to-HTML filters, the single biggest source of inspiration for Markdown’s syntax is the format of plain text email.

[tptacek]

Worth adding that it's said that since 2004, when archive.org first noticed the page.