The Markdown vs. WYSIWYG discussion goes along the same lines as the vim vs. Word discussion. You can discuss it, but real users in the target audiences of the products simply don't care about the alternative. To each his own.
good point. I've never met any client that would like to write in markdown though, but I love it, tbh. My most desirable feature of markdown editor is drag&drop images that turns automatically into `` tags - I wish more editors offer such feature.