In my defence, the comment I was replying to mentioned "renderers" and "converters". Furthermore IMHO, any text editor is a Markdown reader. If you want it formatted as is it were "markup" then might I suggest converting to e.g. PDF using Pandoc and then using one of the many capable viewers.

Noted, re the other comment.

But... come on. You might just as well say any text editor is a browser, because you can technically read HTML with it.

You can also technically read Word documents with a text reader.

I see your point, and maybe it's a matter of preference, but I really do use my text editor for reading Markdown. I wouldn't do the same for a Word doc or HTML, without at least running it through a convertor first.