For the majority of the population, a Markdown editor, much as I would like it (if only because I'd not get frustrated by Reddit's _italic_ vs. HN's stars) would be confusing. WYSIWYG or WSYWYM editors with structural elements (headers, italics, quotes) would be better.

But I also don't think this has any place in the web client. Which has, frankly, come to do too much, poorly, and with vast gaping deficiencies in privacy and security.

I'd far rather, say, that Pocket were my browser. A tool I could use, organise various modes of Web use, strip away almost all site formatting, and, in something that it doesn't now have, present me with an editor.

Which would be a simple GUI WYSIWYM tool by default, but could be swapped out for the user's choice of alternate editor and markup language (within reason).

For me, vim and Markdown. For others, well, whatever idiotic tools you like (that's a joke, boys and girls). But that's the point: to fit your working preferences.

The site could specify its submission format (which ought be something like Markdown, or a very simplified HTML subset), but that could be handled through conversion engines (see Pandoc for an excellent one).

Your initial submission would be maintained in state client-side (and, optionally, replicated to your private or dying-unicorn Cloud provider, Github repo, etc.).

But typing into tiny little text-boxes, with any stray keyboard or mouse move sending me skittering off into oblivion? Fix that shine, to apply some fundamental word substitutions.