[antris]

> Are you saying that NAV etc. aren't valid semantics on applications?

What I mean is that the (supposed) benefits of semantic use of CSS classes go out of the window when you're no longer hosting documents to be read by machines. And the user does not care if the classes of HTML elements are semantic or not.

[KoehlerBear]

Some users do, assistive technologies can benefit significantly from semantic HTML and class names.

[rowanmanning]

Semantic HTML elements, yes, but CSS class names are ignored by assistive technology at large.