tl;dr - WYSIWYG fails to provide enough control for designers. Instead, we should use this specific jQuery library. It shows the markup instead of what it will look like to the end-user.
... No. WYSIWYG is designed to let you preview your document as you go, instead of having to repeatedly preview it and fix things. It's not really for designers, it's for the common man who just want to put something in bold without a ton of extra garbage in his way. It's designed for the common man who doesn't know, or doesn't want to think about, markup.
There's nothing wrong with WYSIWIG editors. The problem is that you are trying to use them for the wrong thing.