In both cases, I get that some users can't or don't like to use a machine grammar/markup, however simple. For some people markup is bad UX. Give them a WYSIWYG; that's fine.
But don't remove the markup editor if your WYSIWYG editor is anything but a perfect one-two-one replacement for markup (and I have never seen one that satisfies that).
IIRC there was a time when Confluence axed their markup, and inevitably a table or a template would get completely screwed, and there was nothing you could do but recreate it. TERRIBLE design.