[leppr]

> The output of web design is, ultimately, HTML and CSS

The output of web design is ultimately a rendered, interactive webpage. We approve or reject websites by viewing them in a browser, not by looking at their code.

> a designer without full mastery of at least HTML and CSS doesn't really deserve his title.

Add to this the fact that the vast majority of web developers are very far from having a "mastery" of HTML and CSS. It's a huge API full of hacks and pitfalls.

Teach rudimentary HTML and CSS to a designer and they'll begin to think in that rudimentary interface, forgetting a competent developer with their far greater arsenal of tricks and tools can actually implement any UI they could imagine.

Your argument could apply to a field where the path from idea to end product is more straightforward. For instance, a comic book writer is expected to master the full pipeline from idea to colored page. A Disney concept artist on the other hand, is absolutely not required to know anything about 3d modeling. Web design mostly falls into that later category, we don't want our designers' creativity burdened by our medium's tedium.