Jay, with all due respect, you're a programmer. You're comfortable with codes and so on. You'd probably be fairly comfortable with HTML too. You're probably also comfortable with command lines. Most people are not. It doesn't matter how simple you make it--many people are going to be put off by markup of any kind. I know many such people: anything resembling codes makes them instantly uncomfortable. "Screw them" is not a productive answer.
As for the problem at hand: quite simply, a WYSIWYG editor that implements all of our wikisyntax is totally impossible. It's way, way too complicated to implement smoothly in Javascript. But you know, the entire *point* of using wikisyntax rather than HTML is to make editing *easier*. If it stands in the way of creating an easier-to-use interface, don't you think it's outlived its usefulness?
So how about this. Design a WYSIWYG editor that works with cleaned HTML, plus whatever syntaxes aren't replicable in HTML. Make sure this editor is high-quality, and then make it the default editor. Then, anytime someone requests a section or page, just convert all the wikisyntax (tables, bold, italics, headers, etc.) into HTML before sending it, so it will work with the WYSIWYG. Then, the user saves it, and the wikisyntax is converted irreversibly to HTML. But the underlying representation will no longer be important to most users; anyone who wants to edit it directly is probably hardcore enough to deal with HTML in any case. This would have a side benefit of greatly simplifying wikitext parsers, ours included (we can even assume that the submitted HTML is XML-compliant!).
So does anyone see any reason to keep wikisyntax at this point, beyond what actually needs to be parsed beyond sanitization?