Right. That's a human problem, though. Many designers have told us they feel very restricted in wysiwyg tools, so refuse to use them.

That makes a lot of sense: most WYSIWYG tools end up presenting a UI that cares more about appearance than semantics, so if you actually care about building good semantic HTML and complementary presentational CSS, most WYSIWYG tools utterly fail. So if a designer cares about building fluid layouts and semantic content rather than pixel-accurate recreations of Photoshop images, it makes sense that they'd feel very restricted in a WYSIWYG tool.