I always have a hard time understanding why anyone would want a dedicated markdown editor in the first place.

Obviously I am not the intended audience for them, but for me markdown is a fundamentally plain text format, Make nice looking plain text, and if you keep to certain well known patterns, you get a chance to run it through a typeset engine. Most of the point being the plain text. If the point were the typeset document, I would pick a better language.

As such, the ideal markdown editor is a text editor.