Funny that we feel so different about Markdown.
The whole point of Markdown (in my opinion) is that the formatting is a function of text that you can see and edit. The entire state of the document is visible, and there are no formatting operations you have to learn, just regular text editing operations like backspace, copy, paste, and so on. For example, if you press backspace, you always know exactly what the result will be: it will delete the character to the left of the cursor.
This is not so in rich text editors; when you press backspace, it changes both the document and invisible internal state, and you can't easily predict what will happen simply by looking at the screen; you need to be aware of the invisible formatting structure, or perhaps a recent history of things you did, or it might be entirely impossible to tell because it depends on some invisible state that was created weeks ago and saved in the document file.
For this huge advantage in predictability and simplicity, Markdown sacrifices formatting power (you can only do a limited set of things like headings, lists, bold, and italic).
That's why Markdown tools that hide the markup are, in my opinion, the worst of both worlds: you sacrifice formatting power, and you sacrifice editor predictability. After the markup is gone, how do you edit it? How do you unbold something, or change the indentation of a list? If there are separate commands for all that, then there was no point in using Markdown.