This reminds me of Atlassian's god-awful WYSIWYG editor. 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…
I really regret going with Atlassian here; I would have advised against it if I knew about this. I will definitely advise against it in the future.