The problem with Markdown is its embarrassingly poor support for highly structured documents. Something as simple as writing a multi-level list interspersed with complete paragraphs is a nightmare to do in Markdown. Tables and images aren't a big improvement over LaTeX and require special syntax to scale and position.
I'd rather use Word for simple documents so I can enjoy drag and drop and graphical image positioning and scaling and easy tables and leave LaTeX for complex documents. Markdown is the worst of both worlds.
However, I could see myself using the much superior Asciidoc (vs Markdown) instead of LaTeX, but unfortunately, the worse-is-better philosophy is still alive and has made Markdown the defacto simple markup language, and tool support for Asciidoc is as poor as LaTeX, so I just go directly to LaTeX instead.
AsciiDoc is essentially XML DocBook with a simpler syntax. It has enough structural constructs for large documents. Also DocBook was designed as master format, and is easily render-able into various outputs forms like for printing and for web pages.
I'd rather use Word for simple documents so I can enjoy drag and drop and graphical image positioning and scaling and easy tables and leave LaTeX for complex documents. Markdown is the worst of both worlds.
However, I could see myself using the much superior Asciidoc (vs Markdown) instead of LaTeX, but unfortunately, the worse-is-better philosophy is still alive and has made Markdown the defacto simple markup language, and tool support for Asciidoc is as poor as LaTeX, so I just go directly to LaTeX instead.