> Mark down is great because it doesn't define a bunch of things. Headline? Its a headline, no font, no sizing, no colors... Just a headline. It means that it can be displayed on any device, printed on any paper, work with any accessibility tool and optimized for what ever requirements the reader has, not what ever the writer thought looked good.

You know, like when you write <h2> in HTML or \section{} in LaTeX?